分解因式： (1)x^2+6xy+8y^2 (2)1-x^2+2xy-y^2

题目

分解因式： (1)x^2+6xy+8y^2 (2)1-x^2+2xy-y^2

答案

(1)x²+6xy+8y²
=(x+2y)(x+4y)
(2)1-x²+2xy-y²
=1-(x²-2xy+y²)
=1-(x-y)²
=(1+x-y)(1-x+y)