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Polynomial Long Division Calculator

Divide polynomials exactly. Explore quotient, remainder and step-by-step subtraction in columns aligned by power, including fractions and missing terms.

Use x and powers such as x^3. Fractions, dot decimals and parentheses work: 1/2*x, 0.5x, (x+1)^2. Degree up to 12.

Quotient
2x + 3
Remainder
−3x + 2

The remainder has degree 1, below the divisor’s degree 2.

Check the exact identity

2x³ + 3x² − x + 5 = (x² + 1) × (2x + 3) + (−3x + 2)

The division equals (2x + 3) + (−3x + 2)/(x² + 1), wherever x² + 1 ≠ 0.

Multiplying the divisor by the quotient and adding the remainder reproduces every coefficient of the dividend exactly.

Cancel one leading term at a time

Step 1 of 2

Divide leading terms: 2x³ ÷ x² = 2x.

Multiply the divisor: (2x) × (x² + 1) = 2x³ + 2x.

Subtract each coefficient in its own power column
Powerx³x²x1
Before23−15
Subtract2020
After03−35

Missing powers have coefficient 0. Subtract the signed coefficient: subtracting −2 adds 2. Wide tables scroll within this panel.

After subtraction: 3x² − 3x + 5. The x³ term is now zero.

Quotient so far: 2x.

All division steps

1. Divide 2x³ by x² to get 2x; subtract 2x³ + 2x to leave 3x² − 3x + 5.

2. Divide 3x² by x² to get 3; subtract 3x² + 3 to leave −3x + 2.

What does the remainder mean?

Polynomial division gives P = D × Q + R. The nonzero remainder has lower degree than the divisor. If R = 0, the divisor is a factor of the dividend. If the divisor has higher degree than the dividend, the quotient is 0 and the dividend itself is the remainder. A nonzero constant divisor always gives remainder 0.

Repeat: divide the leading terms, multiply the whole divisor, then subtract like powers. Stop when no further polynomial quotient term is possible. The exact identity is valid for every x; the expression P/D is defined only where D is not zero.

For division of numbers, use the long division calculator. For arithmetic with fractions, use the fraction calculator.

Supported notation and limits

Use one variable, lowercase x, and +, −, *, /, ^ and parentheses. Use a dot for finite decimals. Exponents must be whole numbers from 0 to 12; −x^2 means −(x²), while (−x)^2 is positive x². Multiplication may be implicit in 2x, 2(x+1), x(x−1) and (x+1)(x−1); use * between numeric factors. Multiplication and division are processed from left to right: 1/2x means (1/2) × x. Use 1/(2x) only as the main division, with 1 in the dividend and 2x in the divisor.

Division inside an input is allowed only by a nonzero constant, such as x/2 or (x+1)/3. Equations, other variables, functions, negative or fractional powers and polynomial denominators inside an input are not supported. Limits per input: 2,000 characters, 512 tokens, 32 nested parentheses and 24 digits per numeric literal. Every intermediate polynomial must have degree at most 12; reduced rational coefficients are limited to 1,024 digits and the calculation to 50,000 work units. Expressions exceeding these limits keep your input and show an error.

All answers and steps use exact rational arithmetic. No rounded decimal is fed back into the calculation. This tool performs polynomial long division, not a root search, factorization or synthetic division.

Method reference: OpenStax College Algebra 2e, §5.4: Dividing Polynomials.

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