已知:x﹣2y=﹣3,则5(x﹣2y)2﹣3(x﹣2y)+40的值是( )
A:5
B:94
C:45
D:﹣4
(Ⅰ)求实数a的取值范围;
(Ⅱ)设x1和x2分别是f(x)的两个极值点且x1<x2,证明: x1x2>e2 .
-- _______?
-- She is a doctor.