Question

Срочно даю 64 балла..................,.

Answer 1

$\frac{d^2r-2dr^2}{\frac{dr}{6} } +\frac{25r^3-2dr^2}{r^2} =\frac{6dr(d-2r)}{dr}+\frac{r^2(25r-2d)}{r^2}=6(d-2r)+25r-2d=6d-12r+25r-2d=4d+13r.$