TeX source:

\begin{align} |+\rangle\langle+||0\rangle\langle0||+\rangle\langle+| &= \dfrac{1}{2}|+\rangle\langle+|, \\ |+\rangle\langle+||1\rangle\langle1||+\rangle\langle+| &= \dfrac{1}{2}|+\rangle\langle+|. \end{align}