Question

x^4-3xy-10y^2+x+9y-2

Answer 1

添项、拆项,得

x^2-3xy-10y^2+x+9y-2

=(x+2y)(x-5y)+2x+4y-x+5y-2

=(x+2y)(x-5y)+2(x+2y)-(x-5y+2)

=(x+2y)(x-5y+2)-(x-5y+2)

=(x+2y-1)(x-5y+2)