9=3^2
3^(2x)=(3^2)^(3x-4)
3^(2x)=3^(6x-8)
2x=6x-8
0=4x-8
8=4x
2=x
Okay so.
A is 4.95
B is 4.95
C is 4.95
D is 4.95
E is 0.495
So I guess E is the Answer! :)
For these problems you have to use PEMDAS so for problem 15 you would do the parentheses first, (21-3) you get 18 and then exponents, 3^2, you get 9, no multiplication but there is division so take your answers, 18 and 9 and divide them, you get 2, so the answer to 15 is 2.