【(x+y+z)^2-(x-y-z)^2化简是因式分解】
(x+y+z)^2-(x-y-z)^2化简
是因式分解
(x+y+z+x-y-z)(x+y+z-x+y+z)
=2x(2y+2z)
=4x(y+z)