设a>0,b>0,a+b=1.则a^xb^x+1/a^xb^x为?

Question

设a>0,b>0,a+b=1.则a^xb^x+1/a^xb^x为?

Answer 1

x=a/b
a=bx
(a-b)/(a+b)=(bx-b)/(bx+b)=(x-1)/(x+1)