Answer:
x=13
Step-by-step explanation:
set up the equation:
AXB+BXC=AXC
(2x+10)+(2x+10)=(6x-6)
calculate for x
x=13
When the value of x is 3, evaluate;

Substitute for the value of x into the parenthesis;

ANSWER:
The expression equals 40 (when x = 3)
7) 26%
8) 188
9) 20
10) Can't read 10
12) 192
13) 2.5%