Question

(x^2-y^2)/[x^2-(y-z)^2]/[x^2+2xy+y^2]/[(x-y)^2-z^2]*[x^2+xy-

Answer 1

(x^2-y^2)/[x^2-(y-z)^2] ÷ [x^2+2xy+y^2]/[(x-y)^2-z^2] × [x^2+xy-xz]/[x^2-xy]

=(x-y)(x+y)/(x+y-z)(x-y+z) × (x-y+z)(x-y-z)/(x+y)(x+y) × x(x+y-z)/x(x-y).因式分解

=(x-y-z)/(x+y) .约去相同项