So first, you get the absolute value to one side:
\(|5x|+5=45\\
|5x|=40\)
Next, set up two equations; One where the value inside the absolute value lines is positive, and another where it is negative, and solve both for the variable:
\(|5x|=40\\5x=40\\x=\frac{40}{5}=8\\\\-5x=40\\x=\frac{40}{-5}=-8\)
Your answers are 8 and -8, or +-8.
