I would try and optimize the sum at the bottom a bit. Definitely we need parentheses around the −1, but just throwing them in will cause a bit of a mess:
Plus, math that’s not typeset well already gives me a less-than-stellar vibe; I’m not a huge fan of the font there.
Instead, you could rewrite the sum a bit, if you have the space for it. The version below takes up only slightly more vertical space than the Sigma, if vertical space is a concern. It’s a bit less cluttered, and LaTeX’s job (technically Mathjax here) is to make sure the typesetting is as good as possible.