For this case we must find the value of the variable "x" of the following equation:

We multiply by 3 on both sides of the equation:

We divide between 2 on both sides of the equation:

We subtract 7 on both sides of the equation:

Answer:
Option B
The answer is 0
Let me tell you why
first plug in the numbers
.5(18+14)-(18-14)^2
(9+7)-(4)^2
16-16
0
You need to know these two formulas:

For example,
