Normal flow

I am a paragraph of text $x+1$ with math inline.

Fraction Alignment

text $\frac{x+1}{2}$

text $x+\frac{x+1}{2}$

Operator Stretching

text $(x+\frac{x+1}{2})$

text $y\left(\prod _x\frac{x+\frac{x+1}{2}}{x+\frac{x+1}{2}}\right)$

text $\left[\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ b_{21}& b_{22}& b_{23}\\ c_{31}& c_{32}& c_{33}\end{array}\right]$