Line break and escaping of % in math / Latex fomulae in README.md

Dear GitLab users,
I have few issues with mathematical formulae which are embedded in Markdown in e.g. README.md. Consider the following example:

\frac{2.7\%}{100} \\ x = 1

When entered here, one can see that percent character is rendered and there is a line break in formulae. However these two do no work in README.md when entered within math block.

Any suggestions how to overcome the issue? Thanks!