If (2 1/2)^4y =1/8 then y =
A. -4
B. -1/8
C. 7/8
D. 3/2
E. 21/16
If you mean
2*(1/2)^(4y) = 1/8, then
(1/2)^(4y) = 1/16
(1/2)^1 = 1/2
y = 1
well, that didn't work.
As written, you have (sort of)
(5/2)^(4y) = 1/8
4y log(5/2) = -log8
That's not getting us anywhere.
So, just what did you mean? what's the (2 1/2) doing there?