There is no way.
However, you can turn off Beautiful Math of Jetpack and use WP QuickLaTeX instead. The font of WP QuickLaTeX can be adjusted.
After installing WP QuickLaTeX, set it to work site wide, so that you don’t have to put [latexpage] everytime you want to use LaTeX. You can now input latex inline using $..$ and standalone using \[..\] .
Also, switch off Photon of Jetpack, as WP QuickLaTeX serves the LaTeX in SVG causing the Photon image delivery to not work. Or, if you want to keep Photon, set WP QuickLaTeX to output in GIF or PNG instead.