Question

(a-b+c)totul la puterea a2a este ...... ?

Answer 1

$(a-b+c)^2=(a-b+c)(a-b+c)= \\ =a^2-ab+ac-ab+b^2-bc+ac-bc+c^2= \\ =a^2+b^2+c^2-2ab+2ac-2bc$