Let I (x)=∫ (d x)/((x-11)^(11/13)(x+15)^(15/13)). If I (37)- I (24)=1/4(1/(b^(1/13))-1/(c^(1/13))), b, c ∈ N, then 3( b + c ) is equal to

Let $\displaystyle \mathrm{I}(x)=\int \frac{d x}{(x-11)^{\frac{11}{13}}(x+15)^{\frac{15}{13}}}$. If $\displaystyle \mathrm{I}(37)-\mathrm{I}(24)=\frac{1}{4}\left(\frac{1}{\mathrm{~b}^{\frac{1}{13}}}-\frac{1}{\mathrm{c}^{\frac{1}{13}}}\right), \mathrm{b}, \mathrm{c} \in \mathbb{N}$, then $\displaystyle 3(\mathrm{~b}+\mathrm{c})$ is equal to