Question

HELP!!!URGENT!!!!!30 puncte

Answer 1

Reamintesc formulele de calcul prescurtat:

$(a+b)^{2}=a^{2}+2ab+b^{2}$

$(a-b)^{2}=a^{2}-2ab+b^{2}$

$(a+b)(a-b)=a^{2}-b^{2}$