why in the problem simplify 8/4^2/3 are we multiplying by one more cube root of 4 (without the exponent 2, or ^3√4) when in other problems ( like simplify 12/^4√9) we multiply by ^4√3^2 which includes the exponent 2? I guess what I'm trying to say is what makes the problems different so that we drop the exponent in the first one but keep it in the other problem when we are multiplying the numerator and denominator?