TeX source:

\displaystyle\require{cancel}\begin{align}\lambda&=\frac{h}{mv}\\&= \displaystyle\frac{6.626\times10^{-34}\,\,\, \displaystyle\frac{\cancel{\text{kg}}\cdot\text{m}^{\cancel{2}}}{\cancel{\text{s}}}      } {\left(0.145\cancel{\text{kg}}\right)\left(46.7\displaystyle\frac{\cancel{\text{m}}}{\cancel{\text{s}}}\right)} \\ \\ &=9.78\,\,\times\,\,10^{-35}\,\,\text{m} \end{align}