solve for x: 8^x=(1/64)^(x-4)

Answer 1

8^x = (1/64)^(x-4),

8^x = (8^-2)(x-4),
8^x = 8^(-2x+8),
If 2 equal numbers have equal bases,their exponents are also equal:
x = -2x+8,
x+2x = 8,
3x = 8,

x = 8/3.