Skip to content

Add and Subtract Polynomials Calculator

Align matching powers. Distribute every sign. See your result take shape.

Build your polynomials

Up to degree 2

POLYNOMIAL 1 · P₁(x)

P₁(x) = x² + 2x + 3

POLYNOMIAL 2 · P₂(x)

P₂(x) = x + 1
YOUR OPERATION(x² + 2x + 3) − (x + 1)
Subtract the whole second polynomial.
The minus sign changes every term in P₂, including negative terms.

Finite decimals and scientific notation · up to 60 significant digits per coefficient; exponent −100 to 100.

RESULTING POLYNOMIAL · P₁ − P₂x² + x + 2

Like terms combined · written in descending powers.

Degree2 · Quadratic
Leading coefficient1
Constant term2

Three curves. One operation.

Pointwise difference
– – P₁(x)– – P₂(x)━━ Result
-4048121620-4-3-2-10123xyShared axes · the result is P₁(x) − P₂(x) at every x
AT x = 16 − 2 = 4Subtract the y-values at the same x.
stcalculator.online

Distribute. Group. Simplify.

Step by step
1Write the subtraction(x² + 2x + 3) − (x + 1)
2Distribute −1 to every term in P₂x² + 2x + 3 − x − 1
3Group terms with the same powerx² + (2 − 1)x + (3 − 1)
SIMPLIFIED RESULTx² + x + 2

Align matching powers

Coefficient balance
PowerP₁P₂Difference
x²101 − 0 = 1
x212 − 1 = 1
Constant313 − 1 = 2
A missing term has coefficient zero.
P₂ has no x² term, so its x² coefficient is 0.

Only terms with the same variable and exponent can be combined.

QUADRATIC TERMS(1 − 0)x² = x²
LINEAR TERMS(2 − 1)x = x
CONSTANT TERMS3 − 1 = 2

−(−3x + 2)
= +3x − 2

A minus sign belongs to every term.

Subtracting a negative coefficient becomes addition. Flip each sign first, then combine matching powers.

stcalculator.online

Formula & interpretation

P₁(x) ± P₂(x)
= (a₁ ± a₂)x² + (b₁ ± b₂)x + (c₁ ± c₂)

Add or subtract corresponding coefficients. Keep each power of x unchanged, then remove zero terms.

The degree can decrease.
When leading terms cancel, the result may be linear, constant, or the zero polynomial.

Frequently asked questions

Why write x instead of 1x?

A coefficient of 1 is omitted on variable terms. A coefficient of −1 is written as a minus sign.

What is the degree of the zero polynomial?

Its degree is undefined under the standard elementary convention. A nonzero constant has degree 0.

Why do signs change during subtraction?

Subtracting a polynomial multiplies every term of that polynomial by −1.

Does this builder accept higher-degree polynomials?

This coefficient builder supports degree 2 and below. The same like-term rules apply to higher degrees.

Sources & Reference Guides

Independent educational reference · No institutional endorsement or expert review claimed.

↗ Math

Align matching powers. Distribute every sign. See your result take shape.

Page information

Updated: October 10, 2026