|
(1)
=a+b ab
;a2+ab a2b
(2)
═x2+xy x2
=x(x+y) x2
;x+y x
(3)
=9mn2 36n3
=9n2•m 9n2•4n
;m 4n
(4)
=x2+2xy+y2 x2-y2
=(x+y)2 (x+y)(x-y)
.x+y x-y
故答案为:(1)a2+ab;(2)x;(3)4n;(4)x-y;
|
(1)
=a+b ab
;a2+ab a2b
(2)
═x2+xy x2
=x(x+y) x2
;x+y x
(3)
=9mn2 36n3
=9n2•m 9n2•4n
;m 4n
(4)
=x2+2xy+y2 x2-y2
=(x+y)2 (x+y)(x-y)
.x+y x-y
故答案为:(1)a2+ab;(2)x;(3)4n;(4)x-y;