9^(2x-1)=4^x
9^2x/9=(2^2)^x=2^2x
9^2x/2^2x=9
(9/2)^2x=9
2x=log(9/2) 9
x=(1/2)[log(9/2) 9]=log(9/2) 9^(1/2)
所以x=log(9/2) 3