math
posted by bob on .
(6) Which equation is equivalent to
4^x=8?
a. log8 4=x
b. logx = 4
c. log x 4=8
d. log 4 8= x

1/4^x = 8
4^x = 1/8
x log4 (4) = log4 (1/8)
but log4 (4) = 1 because b^logb(a) = a
x = log4(1/8) = log4(1)  log4(8)
but log4(1) = 0 for the same reason
so
x = log4(8) or x = log4 (8)