Question

分解因式x*2+2xy-3y*2（注：x*2和y*2分别表示x的二次方和y的二次方）

Answer 1

x^2+2xy-3y^2=x^2+y^2+2xy-4y^2=（x+y)^2-4y^2=(x+y-2y)(x+y+2y)=(x-y)(x+3y)