## Calculus 10th Edition

$13x - \frac{1}{2}x^{2} + C$
$\int (13-x) dx$ = $\int 13 dx - \int x dx$ = $\int 13x^{0} dx - \frac{x^{1+1}}{1+1} + C'$ = $\frac{13x^{1}}{1} - \frac{x^{2}}{2} + + C$ = $13x - \frac{1}{2}x^{2} + C$ The result can be checked by differentiating, and it works.