Question

A and b are positive integers. Find −2a+3b if a^3*b^2=72.

Answer 1

`{a}^(3) {b}^(2) = a * a * a * b * b \\ 72 = 2 * 2 * 2 * 3 * 3 = {2}^(3) {3}^(2) \\ {a}^(3) {b}^(2) = 72 \\ \Rightarrow a = 2,b = 3 \\ \Rightarrow - 2a + 3b = - 2 * 2 + 3 * 3 = - 4 + 9 = 5`