Solve each equation. Check your solution.

$4=\frac{-3u-\left(-7\right)}{-8}$

An equation is an expression containing two quantities separated by a $=$symbol.

Finding a solution to an equation involves separating the variable on one side of the equation and numbers on the other side.

We can add or subtract the same quantities on both sides of the equation for separating the variable on one side of the equation and the numbers on the other side.

We have the equation $4=\frac{-3u-(-7)}{-8}$, we multiply by$-8$ both sides of the equation as shown:

$\begin{array}{l}4\times \left(-8\right)=\frac{-3u-(-7)}{-8}\times \left(-8\right)\\ -32=-3u-(-7)\end{array}$

Simplifying, we get:

$\begin{array}{l}-32=-3u-(-7)\\ -32=-3u+7\end{array}$

We can add or subtract same quantities on both sides of the equation for separating the variable on one side of the equation and the numbers on the other side.

We are given the equation $-32=-3u+7$, we add$-7$ to both sides of the equation as shown:

$\begin{array}{l}-32-7=-3u+7-7\\ -39=-3u\end{array}$

We have the equation $-39=-3u$, we divide by$-3$ both sides of the equation as shown:

$\begin{array}{l}\frac{-39}{-3}=\frac{-3u}{-3}\\ 13=u\\ u=13\end{array}$

Thus, the solution of the equation is $u=13$.

We substitute the value of the variable into the given equation:

$\begin{array}{l}4=\frac{-3u-(-7)}{-8}\\ 4=\frac{-3\times 13-(-7)}{-8}\\ 4=\frac{-39+7}{-8}\\ 4=\frac{-32}{-8}\\ 4=4\end{array}$

Since the above equation is satisfied, the solution $u=13$is verified.