1.if f(x)=8^x, find the value of f(2/3)

2. If 8^2x=2^(x+5), what is the value of x?

8^(2/3) = [ 8^(1/3) ]^2 = 2^2 = 4

(2^3)^(2x) = 2^(x+5)

2^(6x) = 2^(x+5)

6 x = x + 5

5 x = 5

x = 1