设a=2^x,b=3^x
那么方程是：3a^2+2b^2=5ab
(3a-2b)(a-b)=0
(1):3a-2b=0
3*2^x=2*3^x
(2/3)^x=2/3
x=1
(2)a-b=0
3^x=2^x
(3/2)^x=1
x=0