(2^2 * 2^3) / (2^4) =
2^5 / 2^4 =
2^1 <== answer is B
** when multiplying exponents with the same base, keep the base and add the exponents. 2^2 * 2^3 = 2^(2 + 3) = 2^5
** when dividing exponents with the same base, keep the base and subtract the exponents. 2^5 / 2^4 = 2^(5 - 4) = 2^1
