solve for x and im completely lost as to what to do.
4^2x+5 = 8^3x
Change to base 2: 2^(4x+10) = 2^(9x), since 4 = 2^2, and 8 = 2^3.
4x+10 = 9x
x = 2 <==Answer
Jess another slightly different way to solve this is to take logs of both sides of the equation giving
(2x+5)log4 = 3xlog8 rearranging gives
2x + 5=3x (log8/log4) now you can use your calculator to look up the logs or remember that the log of 4 base 2 is 2 and log8 base 2 is 3 so now we have
2x + 5 = 3x(3/2) or
(9/2)x - (4/2)x = 5 which is the same as
(5/2)x = 5 or x = 2 QED