College Algebra: 4/(10^(2x)-7)=2

It says round to 3 decimal places. Now the book says x=0.477 but i got something different? I ended up with 2x=(log18)/(log20) which gives me x=.482

Can someone give me an answer if mine is wrong or is it just a typo in my book?

4
----------------- = 2
10^(2*x) - 7

10^(2*x) - 7 = 2

10^(2*x) = 9

2*x*ln(10) = ln(9)

x = ln(9)/(2*ln(10))

x = 0.4771212546

http://www.wolframalpha.com/input/?i=4%2…

Go with the book, that's what the teacher checks against.