Use the Laplace Transform Integral to find the Laplace Transforms of the following signals: \text { (a) } x(t)=3 u(t)-3 u(t-3) \text { (b) } y(t)=r(t)-r(t-1)-u(t-3) \text { (c) } w(t)=10 u(t)-10 e^{-t} u(t)