條件如圖，請問如何求出x?

2log2/logx=log2x/log2=(log2+logx)/log2
交叉相乘得 logx(log2+logx)=2(log2)^2
(logx)^2+log2logx-2(log2)^2=(logx-log2)(logx+2log2)=0
logx=log2, x=2(不合), logx= -2log2=log2^(-2)=log(1/4), x=1/4

設y=log x/log 2
2/y=1+y
2=y+y^2
y^2+y-2=0
y=1 or y=-2
log x/log 2=1 log x/log 2=-2
x=2(delete) or x=0.25