Question

Answer 1

Bài 1: 

\(\left(x+1\right)^2=x^2+2x+1\)

\(\left(3-a\right)^2=a^2-6a+9\)

\(\left(x+2\right)\cdot\left(x-2\right)=x^2-4\)

\(\left(x+2\right)\cdot\left(x^2-2x+4\right)=x^3+8\)

Answer 2

Bài 2:

a:3(x-y)-x(x-y)=(3-x)(x-y)

b:(3x)^2-y^2=(3x+y)(3x-y)