1.方程(log5 x)²+2log25x-2=0的解集是

1.方程(log5 x)²+2log25x-2=0的解集是
1.方程(log5 x)²+2log25x-2=0的解集是

1.方程(log5 x)²+2log25x-2=0的解集是
令log5 (x)=t
则log25 (x)= 1/2* log5(x)=t/2
方程化为：t^2+t-2=0
(t+2)(t-1)=0
得：t=-2,1
故x=5^t=1/25,5

令log5 (x)=t
则log25 (x)= 1/2* log5(x)=t/2
方程化为：t^2+t-2=0
(t+2)(t-1)=0
得：t=-2, 1
故x=5^t=1/25, 5