log(√5)(5^x+625)-x-log(√5)(2)=4
log(√5)[(5^x+625)/2]=x+4
(5^x+625)/2=(√5)^(x+4)
(√5)^(2x)+625=50(√5)^x
[(√5)^x-25]^2=0
x=log(√5)(25)=4
打的很麻烦,所以有些步骤跳跃了,