分解因式x^2+6xy+8y^2
问题描述：
分解因式x^2+6xy+8y^2
答
原式=x^2+6xy+9y^2-y^2
=(x+3y)^2-y^2
=(x+3y+y)(x+3y-y)
=(x+4y)(x+2y)