๐Ÿ“˜ Lesson 6 of 17 ยท Algebra
Algebra I

๐Ÿงฎ Polynomials

A polynomial is an expression built from variables raised to whole-number powers, combined with addition, subtraction, and multiplication โ€” the workhorse expressions of algebra.

Course progress: 35%

01 Key Concepts

Polynomial Terminology

A monomial has one term (5x), a binomial has two (x+3), a trinomial has three (x^2+2x+1); polynomial covers all of these and more.

Degree of a Polynomial

The highest exponent on the variable in the expression. x^3 + 2x - 5 has degree 3.

Adding and Subtracting Polynomials

Combine like terms (matching variable parts) just as with simpler expressions.

Multiplying Polynomials

Use the distributive property, multiplying every term in the first polynomial by every term in the second (FOIL is a shortcut for two binomials: First, Outer, Inner, Last).

Standard Form

Writing a polynomial with terms in order from highest to lowest degree.

02 Key Formulas

03 Solved Examples

Example 1 Add (3x^2 + 2x - 1) + (x^2 - 5x + 4).
  1. Combine like terms: (3x^2+x^2) + (2x-5x) + (-1+4).
  2. 3x^2+x^2=4x^2. 2x-5x=-3x. -1+4=3.
Answer: 4x^2 - 3x + 3
Example 2 Multiply (x + 3)(x + 5) using FOIL.
  1. First: x*x = x^2.
  2. Outer: x*5 = 5x.
  3. Inner: 3*x = 3x.
  4. Last: 3*5 = 15.
  5. Combine: x^2 + 5x + 3x + 15 = x^2 + 8x + 15.
Answer: x^2 + 8x + 15
Example 3 Find the degree of the polynomial 4x^5 - 3x^2 + 7.
  1. Identify the highest exponent on x.
  2. The term 4x^5 has exponent 5, the highest in the expression.
Answer: Degree 5

04 Practice Questions

1Add (2x^2+3x) + (x^2-x+5).
3x^2+2x+5
2Subtract (5x^2+2x) - (2x^2+4x).
3x^2-2x
3Multiply (x+2)(x+4) using FOIL.
x^2+6x+8
4Find the degree of 3x^4 - x + 2.
4
5Multiply (x-3)(x+3).
x^2-9

๐Ÿ“„ Polynomials โ€” Downloadable Worksheet

10 questions with a full answer key. Grab the PDF to print, or try the interactive version in your browser.