The taxes paid in MX are not selling expenses that adjust your gains. They go on a separate form. I'm not sure where that form is, but if you go to the Search box and type "foreign tax credit" , then select "Jump to" in the results, that should take you to the place in the program to report the foreign taxes you paid.
The credit is described here, by the way.
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-pdf/p514.pdf">https://www.irs.gov/pub/irs-pdf/p514.pdf</a>
