TeX source:

f^{\prime}(x)=f(x) \cdot D(\ln (f(x)))=(2 x+1)^{3}\left(3 x^{2}-4\right)^{7}(x+7)^{4} \cdot\left\{\frac{2 \cdot 3}{2 x+1}+\frac{7 \cdot 6 x}{3 x^{2}-4}+\frac{4}{x+7}\right\}