Remove Number Under x

Here you’ll learn how to get rid of the denominator of a fraction where a variable, such as $x$ , is in the numerator. This is another form of isolating the variable that you need to learn in order to be able to solve equations.

Rule

Removing a Denominator from Under a Variable

1.: Move all the terms containing only numbers over to one side. Remember to change signs.
2.: Move all terms containing $x$ to the opposite side of from the terms containing only numbers. Remember to change signs.
3.: Simplify both sides.
4.: Multiply both sides by the denominator—the number that $x$ is divided by.

Example 1

\begin{array}{l} \frac{x}{3} - 4 & = 3 \\ \frac{x}{3} & = 3 + 4 \\ \frac{x}{3} & = 7 \\ 3 \cdot \frac{x}{3} & = 7 \cdot 3 \\ 3 \cdot \frac{x}{3} & = 7 \cdot 3 \\ x & = 21 \end{array}

Activities 2

Activities 3