若1/a+1/b=2,则a+ab+b/2a+2b=_.
问题描述:
若
+1 a
=2,则1 b
=______. a+ab+b 2a+2b
答
∵若
+1 a
=2,1 b
∴
=2,a+b ab
∴a+b=2ab,
原式=
=(a+b)+ab 2(a+b)
=2ab+ab 2×2ab
=3ab 4ab
.3 4
故答案为
.3 4