Question

(x+7)^2+2(x+7)(x-5)+(x-5)^2 при х 3.5

Answer 1

(x+7)^2+2(x+7)(x-5)+(x-5)^2=(x+7+x-5)^2=(2x+2)^2=(2*3.5+2)^2=9^2=81