okay so first you need to work out the exponents.
(4^3)^2 - you would multiply the two exponents together to get (4^6) which = 4096
second, you do the same thing to the (4^2)^3. multiply the exponents to get (4^6) = 4096.
third, you multiply the two products together: 4096*4096 = 16,777,216