2^x × 5^x
=10^x
=1/10(10^(x-2))^5
(10^(x-2))^5在哪?分子分母?上面(10^(x-2))^5=10^5(x-2)1/10(10^(x-2))^5=10^(5x-10-1)10^x=10^(5x-10-1)x=5x-1111=4xx=11/4