Find the moment generating function corresponding to
(c) $f(x) = \frac{1}{2\beta}e^{-|x-\alpha|/\beta}$, $-\infty < x < \infty$, $-\infty < \alpha < \infty$, $\beta > 0$.
(d) $P(X = x) = \binom{r+x-1}{x}p^r(1-p)^x$, $x = 0, 1, \dots$, $0 < p < 1$, $r > 0$ an integer.