$\displaystyle P(X = k) = \left(\begin{array}{cc}n\\k\end{array}\right)p^kq^ {n-k}$ k=0,...,n.

Where n is a positive integer, 0 < p < 1 , q = 1 - p.

How would I show the mgf of X is

$\displaystyle M_{x}(t) = (pe^t +q)^n\ \ -\infty < t < \infty$

Also, if $\displaystyle Y = \Sigma_{1\le i \le m} X_{i}$

how would I derive the mgf of Y?