Q29 - Geometry

Question

Find the value of the variable.

$8x-2x=90$

Step-by-Step Solution

Answer

The value of the variable is $\mathit{x}\mathbf{=}\mathbf{15}$.

Step 1. Combine the like terms.

To simplify combine the like terms 8x and 2x. 

$\begin{array}{l}8x-2x=90\\ 6x=90\end{array}$

Step 2. Divide by 10.

To find the value of variable x in the equation $6x=90$, divide both sides of the equation by 6.

$\frac{6x}{6}=\frac{90}{6}$

Step 3. Simplify the equation.

To further simplify, cancel the common factors of 6 on both sides.

$\begin{array}{l}\frac{6x}{6}=\frac{6\times 15}{6}\\ x=15\end{array}$

Step 4. Verify the value.

In order to verify the value of x, substitute 15 for x into the equation $8x-2x=90$.

$\begin{array}{l}8\times 15-2\times 15=90\\ 120-30=90\\ 90=90\text{ True}\end{array}$

Hence, the value of the variable is $x=15$.