当a(a-1)-(a^-b)=-2,求a^+b^-2ab/2(b-a)的值
问题描述:
当a(a-1)-(a^-b)=-2,求a^+b^-2ab/2(b-a)的值
答
∵a(a-1)-(a^-b)=-2
∴a²-a-a²+b=-2
a-b=2
(a²+b²-2ab)/2(b-a)
=-(a-b)²/2(a-b)
=-(a-b)/2
=-2/2=-1