(15届江苏初一1试)已知a+b=0,a≠b,则化简ba(a+1)+ab(b+1)得( ) A.2a B.2b C.2 D.-2
问题描述:
(15届江苏初一1试)已知a+b=0,a≠b,则化简
(a+1)+b a
(b+1)得( )a b
A. 2a
B. 2b
C. 2
D. -2
答
(a+1)+b a
(b+1),a b
=b+
+a+b a
,a b
=(a+b)+(
+b a
),a b
又a+b=0,a≠b,可得:
=a b
=-1,b a
∴
(a+1)+b a
(b+1),a b
=(a+b)+(
+b a
),a b
=-2.
故选D.