Pre-Algebra · Quick Reference

Expressions Cheat Sheet

Pre-Algebra · Lesson 2/10

In one line: an expression combines numbers, variables, and operations — but unlike an equation, it doesn't have an equals sign and isn't solved, only simplified or evaluated.

Key Ideas

1What is an Expression?. A combination of numbers, variables, and operations (like +, -, x, /) without an equals sign, such as 3x + 5.

2Terms. The parts of an expression separated by + or - signs. In 3x + 5, the terms are 3x and 5.

3Like Terms. Terms with the exact same variable part, like 4x and 7x (but not 4x and 7x^2). Like terms can be combined.

4Combining Like Terms. Add or subtract the coefficients of like terms while keeping the variable part unchanged.

5Simplifying Expressions. Rewriting an expression in its shortest, clearest form by combining like terms and applying arithmetic.

Worked Examples

Simplify 4x + 3x.

Simplify 5x + 3 + 2x - 1.

7x + 2

Simplify 6y + 4 - 2y + 9.

4y + 13

Practice Yourself

Simplify 5x + 2x.

Simplify 8y - 3y.

Simplify 3x + 4 + 2x.

5x + 4

Simplify 10 - 4y + 6y.

10 + 2y