5(2x-8)+15=-15
First do what is in parenthesis!
You have to multiply "2x and 8 both by 5 because it says 5 of 2x-8's
Then you get:
10x-16+15=-15
Now let's solve -16+15
We then get -1.
10x-1=-15
We need to isolate x to one side so in order to do that we need to add one to both sides, because -1+1 equals 0.
Then we have
10x=-14
Now we really want x to be the only thing on the left side, so we HAVE to divide everything by 10 on both sides.
x=-1.4