Question

(a+1)^2+2(a+1)-3(a-1)(a+1)

Answer 1

(a+1)²+2(a+1)-3(a-1)(a+1)=a²+2a+1+2a+2-3(a²-1)=a²+2a+1+2a+2-3a²+3=a²-3a²+2a+2a+1+2+3= -2a²+4a+6= -2(a²-2a-3)

Answer 2

$(a+1)^2+2(a+1)-3(a-1)(a+1)=\=(a+1)^2+2(a+1)-3(a^2-1)=(a+1)^2+2(a+1)-3a^2+3=\=(a+1)^2+2(a+1)+1+2-3a^2=\=(a+1)^2+2*1*(a+1)+1^2+2-3a^2=((a+1)+1)^2+2-3a^2=\=(a+2)^2-3a^2+2=a^2+4a+4+2-3a^2=-2a^2+4a+6=\=-2(a^2-2a-3)$