\documentclass{article}
\usepackage{unicode-math}

\setmathfont[math-style=upright]{GaramondNo8 Italic}

\begin{document}

\[\sqrt{x+y=z}\]

\[a^2 + b^2 = c^2 \]

Let $p_1, p_2, \ldots, p_n$ be the first $n$ primes\ldots

\[{n \choose m} = \frac{n!}{m!\cdot (n-m)!}\]

\[x_1 + x_2 + \cdots + x_n \]
\end{document}