约分: (1)−35a4b3c21a2b4d, (2)x2−(y−z)2(x+y)2−z2.
问题描述:
约分:
(1)
,−35a4b3c 21a2b4d
(2)
.
x2−(y−z)2
(x+y)2−z2
答
(1)原式=
=-−7a2b3•5a2c 7a2b3•3bd
;5a2c 3db
(2)原式=
=(x+y−z)(x−y+z) (x+y+z)(x+y−z)
.x−y+z x+y+z