All that you have to do is plug in the given values for each of the variables. So, we know that:
A = 3
B = 8
C = 2
D = 5
So, plug in the values.

÷

3^2 = 9
3*8 = 24
2 * 5 = 10
24/2 = 12
9 + 12 - 10 = 21 - 10 = 11.
So, the value of the expression is 11.