# Variables as Unknown Numbers

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

## Overview

Variables can represent unknown numbers. We can use what we know about mathematical operations to determine the value of these unknown numbers. For example…

Determine the value of x in the expression

5x = 35

We can read the expression as 5 times what number equals 35?

We can use the relationship between multiplication and division to solve for x

5x = 35

Divide both sides by 5 to get x by itself.

We can check our answer by plugging the value back into the original equation.

5 (7) = 35 ✔

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