TeX source:

\frac{\mathrm{dV}}{\mathrm{dt}}=\frac{\mathrm{d}\left(\frac{4}{147} \pi \mathrm{h}^{3}\right)}{\mathrm{dt}}=\frac{4}{147} \pi \frac{\mathrm{d}\left(\mathrm{h}^{3}\right)}{\mathrm{dt}}=\frac{4}{147} \pi 3 \mathrm{~h}^{2} \frac{\mathrm{dh}}{\mathrm{dt}} \quad