#### Answer

$ 12c^{3}-9c^{2}-15c$

#### Work Step by Step

Apply the Distributive Property.
$3c(4c^{2}-5)-c(9c)=3c(4c^{2})-3c(5)-c(9c)$
... multiply coefficients and add exponents.
$=12c^{3}-15c-9c^{2} \qquad$...list terms in order of exponents.
$= 12c^{3}-9c^{2}-15c$