Question

метод группировки:1)xy+2y+2x+4
2)y^2a-y^2b+x^2a-x^2b

Answer 1

а)y(x+2)+2(x+2)=(y+2)(x+2)

б)a(y²+x²)-b(y²+x²)=(a+b)(y²+x²)

Answer 2

$xy+2y+2x+4=x(y+2)+2(y+2)=(x+2)(y+2)\\y^2a-y^2b+x^2a-x^2b=a(y^2+x^2)-b(y^2+x^2)=(a-b)(y^2+x^2)$