Question

find the factors of 3m square n + 12 mn square

Answer 1

$3m^2n + 12mn^2 \\ \\ = 3mn\ (m + 4n) \\ \\ \\ \therefore\ Factors are \ 3mn\ and \ m + 4n.$

Answer 2

$3m {}^{2} n + 12mn \\ = 3mn(3m {}^{2} n/3mn + 12mn/3mn) \\ = (3mn)(m + 4)$