x^2-y^2+ 6x +9分解因式
问题描述:
x^2-y^2+ 6x +9分解因式
答
x^2-y^2+ 6x +9
=(x^2+6x+9)-y^2
=(x+3)^2-y^2
=(x+3-y)(x+3+y)
=(x-y+3)(x+y+3)