lg x + lg x^3 + lg x^5 + ``` + lg x^(2n-1)
=lg x + 3lg x+5lg x+……+(2n-1)lg x
=(1+3+5+……+2n-1)lg x
=(n^2)lg x
因 lg x + lg x^3 + lg x^5 + ``` + lg x^(2n-1) =2n^2
所以 (n^2)lg x=2n^2
即得 lg x=2
所以 x=10^2 (提示:这里的lg是对10求对数,它的底数是10)
=100
lg x + lg x^3 + lg x^5 + ``` + lg x^(2n-1)
=lg x + 3lg x+5lg x+……+(2n-1)lg x
=(1+3+5+……+2n-1)lg x
=(n^2)lg x
因 lg x + lg x^3 + lg x^5 + ``` + lg x^(2n-1) =2n^2
所以 (n^2)lg x=2n^2
即得 lg x=2
所以 x=10^2 (提示:这里的lg是对10求对数,它的底数是10)
=100