Free printable worksheet

Factoring Trinomials Worksheet

Twenty monic trinomials with positive and negative factor pairs.

Algebra 1Grades 7-103 pagesAnswer key included

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What this worksheet includes

  • Twenty monic trinomials with positive and negative factor pairs.
  • 3-page printable PDF with a complete answer key
  • Designed for Grades 7-10 algebra 1 practice
  • Available as an immediate free download with no email required

How to use it

Use this factoring trinomials worksheet for guided practice, independent review, homework, tutoring sessions, or a quick skills check. The spacious layout is designed to leave room for students to show their work rather than guess from crowded answer choices.

After students finish, compare their reasoning with the included answer key. When an answer is incorrect, have the student locate the first step where their work changed direction before trying the problem again.

Who this practice is for

This resource is designed for grades 7-10 students working on algebra 1. Teachers, tutors, homeschool families, and parents can preview the first page before deciding whether the level and spacing fit the student.

Looking for a broader sequence? Browse all Algebra I worksheets.

Topic guide

How to approach factoring trinomials

Factoring a monic trinomial reverses polynomial multiplication. For x² + bx + c, look for two integers whose product is c and whose sum is b.

The signs of b and c narrow the choices: a positive constant gives matching signs, while a negative constant gives opposite signs. Multiplying the factors is the fastest way to check the result.

Learning objectives

  • Find factor pairs efficiently
  • Use coefficient signs to choose factors
  • Verify factors by multiplication

Skills to review first

  • Integer factor pairs
  • Combining like terms
  • Multiplying binomials
Worked example

Follow the reasoning step by step

Factor x² + 5x + 6.

  1. List factor pairs of 6: 1 and 6; 2 and 3.
  2. Choose 2 and 3 because 2 + 3 = 5.
  3. Write (x + 2)(x + 3).
  4. Check by multiplying to recover x² + 5x + 6.

Solution: (x + 2)(x + 3).

Try before downloading

Three sample problems

Work each problem, then open the answer to check your result.

Problem 1 · positive factors

x² + 7x + 12

Show answer

(x + 3)(x + 4)

Problem 2 · opposite signs

x² − x − 12

Show answer

(x − 4)(x + 3)

Problem 3 · negative factors

x² − 9x + 20

Show answer

(x − 4)(x − 5)

Error check

Common mistakes to watch for

  • Using factors that multiply correctly but add incorrectly
  • Losing the sign of the middle term
  • Stopping before checking for a greatest common factor