## Intermediate Algebra for College Students (7th Edition)

$-21846$
Here, $a_1=-2, r=-2, n=15$ Now, we have $S_n=\dfrac{a_1(1-r^n)}{1-r}$ Now, $S_{15}=\dfrac{(-2)(1-(-2)^{15})}{1-(-2)}$ or, $=-21846$