9h^2+42h+49 no common factors trial and error try first term and last term all sings are positive since last term and middle terms are possitive factor leading term and coeficient and try those 9=3*3 49=7*7 (3h+7)(3h+7) 9h^2+21h+21h+49 9h^2+42h+49 true (3h+7)(3h+7)=(3x+7)^2 answer is (3h+7)^2 answe ris ths second one