Equation 23.2.399A128F70476F

\begin{equation} \begin{gathered} k\int _0^2C\, \mathrm dr+\int _0^2F\, \mathrm dr=0, \\ l=kC^{-m},\qquad L(C)=-\int _0^2\frac{F}{C^{m+1}}\, \mathrm dr. \end{gathered} \end{equation}