I need help on this problem how do you solve this absolute value?
When solving an absolute value problem, I would isolate the absolute value until you get a form like
|z| = some number
In this case this would invole subtracting 4 from both sides
|z| + 4 - 4 = 9 - 4 ==> |z| = 5
Now that we are here you have to remember that the absolute value is both the positive and negative value. So:
|z| = 5 ==> z = 5 and z = -5