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Polynomial Long Division Calculator

A polynomial long division calculator with six boxes: type the coefficients of your dividend and divisor, and the quotient and remainder appear instantly. The page also teaches the full vertical method, step by step. The polynomial long division calculator form and the lesson share the same six numbers.

Type your division problem — the AI walks through the long division steps

How to use this polynomial long division calculator

Six boxes, one click. Type the coefficients of your dividend and divisor, press Calculate, and this polynomial long division calculator returns the quotient and the remainder at once. The polynomial long division calculator form is pre-filled with the sample below. Press Calculate on those and the polynomial long division calculator answers instantly.

  • Dividend: x³ (0 if quadratic) — the number on x3x^3. Type 0 when your dividend has no cubic term. For x2+3x+5x^2+3x+5, this box of the polynomial long division calculator holds 0.
  • Dividend: coefficient of x² — the number on x2x^2, here 1. The polynomial long division calculator reads it as the second box. The polynomial long division calculator labels every box, so nothing hides.
  • Dividend: coefficient of x — the number on xx, here 3.
  • Dividend: constant term — the plain number at the end, here 5.
  • Divisor: x (in e·x + f) — the number on xx in the divisor, here 1.
  • Divisor: constant (e·x + f) — the plain number in the divisor, here 1 — the last of the six the polynomial long division calculator needs.

Five output rows come back. The first is a check: it reads true when the divisor is valid, so false means you typed e=0e = 0 — the polynomial long division calculator refuses to divide by zero. Three numbers then build the quotient, px2+qx+rp\cdot x^2 + q\cdot x + r. The last row is the remainder R. For the sample numbers above the polynomial long division calculator reads p=0p = 0, q=1q = 1, r=2r = 2, R=3R = 3. So the quotient is x+2x + 2 and the remainder is 3. The polynomial long division calculator prints all five rows at once.

The form covers every dividend up to a cubic divided by a linear divisor ex+fe\cdot x + f. Need a fourth-degree dividend, or a quadratic divisor? The long division polynomials calculator form stops there. The method below still applies to those shapes, and the AI box discusses them with you.

This page is more than a static polynomial long division calculator — it is also an AI tutor you can ask questions:

  • Ask in plain words. "Divide 2x33x2+4x+52x^3 - 3x^2 + 4x + 5 by x+2x + 2." The AI fills the six boxes and runs the polynomial long division calculator on this page for you. Any wording works — the polynomial long division calculator only needs the six numbers.
  • Take a photo of your homework. The AI reads the polynomials and fills the polynomial long division calculator form for you. Photos save typing in the polynomial long division calculator form.
  • Ask about the ideas, not just the answer. "Why do we change the signs when subtracting?" The AI explains each move of the polynomial long division calculator scaffold — every number still comes from the polynomial division calculator on this page.
  • Work backwards, then keep asking. Give a quotient and a remainder and ask what the dividend was. Follow-ups are welcome on this polynomial long division solver page, so keep asking. The polynomial long division calculator form answers either direction.

What is polynomial long division?

Long division of polynomials copies the arithmetic you already know. Divide 178 by 3 and you loop through four moves: divide, multiply, subtract, bring down. You land on 59 with remainder 1, because 178=3×59+1178 = 3 \times 59 + 1. Long division with polynomials runs the identical loop — the columns just hold powers of xx instead of place values. That is why variable long division feels familiar on day one, and why the polynomial long division calculator only needs six numbers to describe the whole job. Feed it those six, and the polynomial long division calculator settles the whole division.

Every division statement has the same shape: the dividend equals the divisor times the quotient, plus the remainder. Every polynomial long division calculator answer fills in that sentence.

x2+3x+5=(x+1)(x+2)+3x^2 + 3x + 5 = (x + 1)(x + 2) + 3

Read the picture. The big rectangle is the part the divisor x+1x + 1 measures off: width x+1x + 1, height x+2x + 2. Its four boxes total x2+3x+2x^2 + 3x + 2. The leftover strip of area 3 is the remainder, too short in degree to extend the height again. The picture is the polynomial long division calculator answer drawn as geometry. Dividing polynomials by long division asks how many times ex+fe\cdot x + f fits — exactly like asking how many threes fit in 178. That single question is what the polynomial long division calculator answers numerically.

A dividing polynomials calculator answers that question with numbers — the polynomial long division calculator rows are that answer, split into parts. A dividing two polynomials calculator that shows its work teaches the question too. This polynomial long division calculator page does both, and the sections below walk the full vertical scaffold that the polynomial long division calculator spares you. Run the polynomial long division calculator form first; the scaffold then becomes a read-along. The polynomial long division calculator is the fast lane; the scaffold is the lesson.

x1x2x2x2+R = 3quotient = x + 2 (left side)
Polynomial long division calculator in one picture: dividing x² + 3x + 5 by x + 1 — the (x + 1) by (x + 2) rectangle covers x² + 3x + 2, and the leftover strip of area 3 is the remainder (drawn to scale at x = 3)

Why this dividing polynomials by long division calculator asks for coefficients

Why six number boxes instead of one big expression? Because a polynomial is fully described by its coefficient list. The dividend ax3+bx2+cx+da\cdot x^3 + b\cdot x^2 + c\cdot x + d and the divisor ex+fe\cdot x + f use exactly six numbers, so this dividing polynomials by long division calculator asks for exactly six. Six boxes, one answer set — the polynomial long division calculator keeps it that simple.

  • A quadratic dividend? Type 0 for a — x2+3x+5x^2 + 3x + 5 is really 0x3+1x2+3x+50x^3 + 1x^2 + 3x + 5. The polynomial long division calculator treats the leading 0 exactly like any other coefficient. Zero is a real coefficient to the polynomial long division calculator.
  • A missing middle works the same way: x33x+2x^3 - 3x + 2 has b=0b = 0. Zero coefficients keep every column in place inside the polynomial long division calculator.
  • The divisor must stay linear here. Dividing by x2+x+2x^2 + x + 2 needs the general method below, which the worked examples make plain. For linear divisors, the polynomial long division calculator form is enough.

The engine behind the polynomial long division calculator form untangles the coefficients directly. With e=1e = 1 the arithmetic is clean bookkeeping. With e=2e = 2 or more, every quotient term still comes from one leading-term division at a time. What this polynomial division calculator computes is exactly what the vertical method produces — the same quotient and remainder, reached without the scaffold. That is the polynomial long division calculator trade: less writing, identical math. The polynomial long division calculator rows even come out in scaffold order.

The formula behind this polynomial division calculator

Every polynomial long division calculator stands on one identity, the Division Algorithm. Divide a dividend f(x)f(x) by a divisor d(x)d(x) and two unique pieces come out: a quotient q(x)q(x), and a remainder r(x)r(x). The remainder is zero, or lower in degree than the divisor. That one line is everything a polynomial long division calculator promises.

f(x)=d(x)q(x)+r(x)f(x) = d(x)\cdot q(x) + r(x)

SymbolMeaning
a,b,c,da, b, c, ddividend coefficients: f(x)=ax3+bx2+cx+df(x) = a\,x^3 + b\,x^2 + c\,x + d
e,fe, fdivisor coefficients: d(x)=ex+fd(x) = e\,x + f
p,q,rp, q, rquotient coefficients: q(x)=px2+qx+rq(x) = p\,x^2 + q\,x + r
RRthe remainder — zero, or a constant once the divisor is linear; the polynomial long division calculator prints it last

Flip the identity around and you get the self-check every division deserves: multiply the quotient by the divisor, add the remainder, and the dividend must reappear. Arithmetic gave 178=(3×59)+1178 = (3 \times 59) + 1. Our sample gives (x+1)(x+2)+3=x2+3x+5(x + 1)(x + 2) + 3 = x^2 + 3x + 5. The polynomial long division calculator rows carry the same identity. The picture shows both bars matching at x=3x = 3: 20 + 3 = 23. The polynomial long division calculator makes the same check one click away.

When R=0R = 0 the divisor divides evenly and becomes a factor of the dividend — the bridge from division to factoring. Run the polynomial long division calculator, multiply back, compare. When the two sides match, your polynomial long division calculator session is done. The polynomial long division calculator check row settles it instantly. One run of the polynomial long division calculator settles every question on this page.

x² + 3x + 5(x + 2)(x + 1)+ 302023both bars are 23 units long at x = 3
The check in one picture: quotient × divisor + remainder rebuilds the dividend — (x + 1)(x + 2) + 3 = x² + 3x + 5, drawn at x = 3 where both bars run 23 units (20 + 3) — the polynomial long division calculator check, drawn to scale

The long division algorithm, step by step

To divide long division polynomials cleanly, every power of xx needs its own column. Then one small loop does all the work — it is how to do polynomial long division in seven moves. The polynomial long division calculator automates them; you should still own them:

  1. Arrange both polynomials in descending powers of xx, inserting a 0 coefficient for any missing term.
  2. Divide the leading term of the dividend by the leading term of the divisor. That is the next quotient term.
  3. Multiply the whole divisor by that new term.
  4. Subtract the product from the current row — change every sign, then add.
  5. Bring down the next term of the dividend.
  6. Repeat steps 2 to 5 until no term is left to bring down.
  7. Stop when the remainder is lower in degree than the divisor, and write it as RR or as a fraction over the divisor. That stop condition is the last row the polynomial long division calculator prints.

Divide, multiply, subtract, bring down — the same four words that run 178÷3178 \div 3. Each pass adds one term to the quotient, so a cubic dividend takes at most three passes. The polynomial long division calculator runs those passes on coefficients alone. The next three examples run the loop by hand, and the polynomial long division calculator rows sit beside them for checking. Trust the polynomial long division calculator for the arithmetic; own the loop for the exam. The polynomial long division calculator sits up top; the loop lives in the examples below.

Example 1 - a quadratic dividend with a remainder

Divide x2+3x+5x^2 + 3x + 5 by x+1x + 1 — the exact numbers sitting in the polynomial long division calculator form on this page. The polynomial long division calculator placeholders are exactly these six.

x+2+5x+1  )    x2+3x+5    x2+x+5  2x+5  2x+2  3\begin{array}{r} x+2\phantom{+5} \\ x+1\;\big)\;\underline{\;x^2+3x+5\;} \\ \underline{\;x^2+x\phantom{+5}\;} \\ 2x+5 \\ \underline{\;2x+2\;} \\ 3 \end{array}

  1. Leading terms: x2÷x=xx^2 \div x = x, so the quotient starts with xx.
  2. Multiply back: x(x+1)=x2+xx(x+1) = x^2 + x. Subtract, bring down: 2x+52x + 5.
  3. Again: 2x÷x=22x \div x = 2. Multiply: 2(x+1)=2x+22(x+1) = 2x + 2. Subtract: 33.
  4. Degree 0 is below degree 1, so 3 is the final remainder. Six numbers in, four numbers out — the polynomial long division calculator economy.

The quotient is x+2x + 2 with remainder 3, so x2+3x+5=(x+1)(x+2)+3x^2 + 3x + 5 = (x+1)(x+2) + 3. Check it by multiplying back — the identity holds exactly. Type 0, 1, 3, 5, 1, 1 into the polynomial long division calculator above and the same four numbers come back: p=0p = 0, q=1q = 1, r=2r = 2, R=3R = 3. This polynomial long division calculator pass is the one the area-model picture draws. The polynomial long division calculator and the scaffold agree term by term. That agreement is the polynomial long division calculator doing its one job.

Example 2 - a missing term and a zero remainder

Divide x33x+2x^3 - 3x + 2 by x+2x + 2. The dividend skips x2x^2, so write it as x3+0x23x+2x^3 + 0x^2 - 3x + 2 before you start — that 0 keeps every column honest. The polynomial long division calculator takes the same dividend with b=0b = 0. Missing terms are where hand work drifts and the polynomial long division calculator does not.

x22x+1+2x+2  )    x3+0x23x+2    x3+2x23x+2  2x23x+2  2x24x+2  x+2  x+2  0\begin{array}{r} x^2-2x+1\phantom{+2} \\ x+2\;\big)\;\underline{\;x^3+0x^2-3x+2\;} \\ \underline{\;x^3+2x^2\phantom{-3x+2}\;} \\ -2x^2-3x\phantom{+2} \\ \underline{\;-2x^2-4x\phantom{+2}\;} \\ x+2 \\ \underline{\;x+2\;} \\ 0 \end{array}

  1. x3÷x=x2x^3 \div x = x^2. Multiply, subtract, bring down: 2x23x-2x^2 - 3x.
  2. 2x2÷x=2x-2x^2 \div x = -2x. Multiply, subtract, bring down: x+2x + 2.
  3. x÷x=1x \div x = 1. Multiply, subtract: 00.

The remainder is 0, so x+2x + 2 divides evenly: x33x+2=(x+2)(x22x+1)x^3 - 3x + 2 = (x+2)(x^2 - 2x + 1). The quotient even factors as (x1)2(x-1)^2. A zero remainder always means the divisor is a factor of the dividend. Run 1, 0, −3, 2, 1, 2 through the polynomial long division calculator and RR comes back 0 — the polynomial long division calculator signature of a factor. When a factor is the goal, the polynomial long division calculator is the fastest test you own. The polynomial long division calculator R-row is that test in one click.

Example 3 - work backwards from the remainder

A student's notebook records a finished division: divisor x+2x + 2, quotient 2x27x+182x^2 - 7x + 18, remainder 31-31. The dividend is smudged out. Rebuild it with the Division Algorithm — multiply, then add:

  1. Multiply the quotient by the divisor: (x+2)(2x27x+18)=2x33x2+4x+36(x+2)(2x^2 - 7x + 18) = 2x^3 - 3x^2 + 4x + 36.
  2. Add the remainder: 2x33x2+4x+36312x^3 - 3x^2 + 4x + 36 - 31.
  3. The dividend was 2x33x2+4x+52x^3 - 3x^2 + 4x + 5. The smudged line matches the polynomial long division calculator output for those six coefficients.

This is also the checking move: after any division, quotient times divisor plus remainder must restore the dividend exactly. Long division examples with polynomials deserve exactly this closing line — make it a habit. The polynomial long division calculator confirms it: type 2, −3, 4, 5, 1, 2 and the rows read p=2p = 2, q=7q = −7, r=18r = 18, R=31R = −31. The polynomial long division calculator rebuilt the smudged line in reverse. Checking is division run backwards, and the polynomial long division calculator rows make it a habit.

Four common polynomial division mistakes

Everyone learning how to long divide polynomials meets these four slips. The polynomial long division calculator page lists them because each one survives into calculus. The polynomial long division calculator catches the arithmetic ones:

  1. Forgetting to change the signs when subtracting. Subtraction means flipping every sign of the lower row, then adding. One missed flip poisons the rest of the scaffold — most wrong answers trace back here.
  2. Dropping missing terms. x33x+2x^3 - 3x + 2 must be written with the 0x20x^2 in place. A missing term is an invisible column, and every later row drifts left. The polynomial long division calculator keeps the column as a typed 0.
  3. Dividing by the whole divisor. Each quotient term comes from leading term divided by leading term only. Trying to divide 3x3x by x+1x + 1 in one bite has no clean answer — the loop exists for a reason. The polynomial long division calculator runs that loop three times for a cubic.
  4. Writing the remainder like a mixed number. Dividing polynomials long division style ends with quotient plus remainder-over-divisor: x+2+3x+1x + 2 + \frac{3}{x+1}. Gluing the fraction on without the plus sign reads as multiplication.

The polynomial division calculator above never drifts columns or drops a sign. The vertical method needs your care for exactly those two habits — the polynomial long division calculator checks them for you. Compare your scaffold against the polynomial long division calculator rows after every problem. The polynomial long division calculator never tires of that comparison.

Problem 1

A community garden is being redesigned. The area of the main plot is 3x2+5x13x^2 + 5x - 1 square meters, and its longer side measures x+3x + 3 meters. Dividing the area polynomial by the side polynomial gives the other side, with a remainder left over. What is that remainder? Check your answer with the polynomial long division calculator above.

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Problem 2

A marching band orders a banner whose area is modeled by 2x39x2+322x^3 - 9x^2 + 32 square feet. The banner's height is the polynomial 2x52x - 5 feet. The supplier divides the area by the height to write the width expression. What remainder does that division leave? Check it with the polynomial long division calculator above.

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Problem 3

A storage box has volume 2x23x+k2x^2 - 3x + k cubic inches and height x+2x + 2 inches, where kk is a number the designer still chooses. The base area is the quotient of the volume divided by the height. The designer wants no leftover material, so the division must be exact. What value of kk makes the remainder zero? Then confirm your kk with the polynomial long division calculator above.

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Frequently asked questions

1

How do I divide polynomials using long division?

Arrange both polynomials in descending powers, insert 0 for missing terms, then loop: divide leading terms, multiply back, subtract, bring down. Repeat until the remainder is lower in degree than the divisor. The polynomial long division calculator on this page runs the same loop for dividends up to a cubic — the polynomial long division calculator automates that exact loop.

2

How to do polynomial long division when a term is missing?

Write the missing term with a 0 coefficient before you start: $x^3 - 3x + 2$ becomes $x^3 + 0x^2 - 3x + 2$. The zero keeps the columns aligned through every subtract and bring down. Example 2 above shows the full vertical layout, and the polynomial long division calculator takes the 0 in its $b$ box, so the polynomial long division calculator column never drifts. The polynomial long division calculator then aligns with your written columns.

3

What does a remainder of zero mean?

The divisor divides the dividend evenly, so both the divisor and the quotient are factors of the dividend. In Example 2, remainder 0 turns $x^3 - 3x + 2$ into $(x+2)(x-1)^2$. The factor calculator linked below takes the story from there. The polynomial long division calculator reports the 0 instantly — its remainder row is that test.

4

How is synthetic division different?

Synthetic division is a shorthand for the special case of a linear divisor with leading coefficient 1. It drops the variables and keeps only the coefficients, but returns the same quotient and remainder. This polynomial long division calculator takes any linear divisor, $e\cdot x + f$, with $e$ other than 1 — the polynomial long division calculator form takes it directly.

5

Can the divisor be a quadratic?

Yes — long division handles any divisor whose degree does not exceed the dividend's. The quotient degree is the difference of the two degrees, and the remainder may itself be a polynomial. Example: dividing $4x^4 + 3x^3 + 2x + 1$ by $x^2 + x + 2$ leaves quotient $4x^2 - x - 7$ and remainder $11x + 15$. The polynomial long division calculator form here covers linear divisors; the vertical method covers what the polynomial long division calculator cannot. For linear divisors, the polynomial long division calculator form is the quick route.

6

Does this polynomial long division solver show its work?

The calculator on this page lists every coefficient of the quotient and the remainder as its own row. The worked examples above show the full vertical scaffold. For any division shaped like the form, that pair is the complete work, ready to copy into homework. The polynomial long division calculator rows map to the scaffold, line by line.

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