What question? Do you need to solve for x? x and X are representing the same thing? If so, why aren't they the same symbol?
I have closed this thread, as it was posted in the wrong forum section. Please start a new thread in the Homework & Coursework section, under Precalculus. Be sure to include what you've tried. Also, your notation is confusing in places. log10 means log, base 10 (or log_{10}). What you have written as log10X probably means log_{10}(x), but it's possible you meant log(10x), with log understood to mean log base 10.