Question

1.(a+b)^2-4b^2 2.9x^2-16(a+b)^2 3.(x+y)^3(x-y)-(x+y)(x-y)^3

Answer 1

1.(a+b)^2-4b^2=(a+b-2b)(a+b+2b)=(a-b)(a+3b)2.9x^2-16(a+b)^2=(3x-4a-4b)(3x+4a+4b)3.(x+y)^3(x-y)-(x+y)(x-y)^3=(x+y)(x-y)[(x+y)²-(x-y)²]=(x+y)(x-y)(x+y+x-y)(x+y-x+y)=4xy(x+y)(x-y)