Q27 - Geometry

Question

Find the value of the variable.

$55=7s-8$

Step-by-Step Solution

Answer

The value of the variable is $\mathit{s}\mathbf{=}\mathbf{9}$.

Step 1. Add 8.

To find the value of variable s in the equation $55=7s-8$, add 8 on both sides of the equation.

$55+\left(8\right)=7s-8+\left(8\right)$

Step 2. Simplify the equation.

To simplify, remove all the brackets and combine the like terms.

$\begin{array}{l}55+8=7s-8+8\\ 63=7s\end{array}$

Step 3. Divide by 7.

To find the value of variable s in the equation $63=7s$, divide both sides of the equation by 7.

$\frac{63}{7}=\frac{7s}{7}$

Step 4. Simplify the equation.

To further simplify, cancel the common factors of 7 on both sides.

$\begin{array}{l}\frac{7\times 9}{7}=\frac{7s}{7}\\ 9=s\end{array}$

Step 5. Verify the value.

In order to verify the value of s, substitute 9 for into the equation $55=7s-8$.

$\begin{array}{l}55=7\times 9-8\\ 55=63-8\\ 55=55\text{ True}\end{array}$

Hence, the value of the variable is $s=9$.