Since $5t^{2}\sinh\!\left(at\right)+7t^{2}\sin\!\left(at\right) = t^2\left(5\sinh\!\left(at\right)+7\sin\!\left(at\right)\right)$, to find the Laplace transform of $5t^{2}\sinh\!\left(at\right)+7t^{2}\sin\!\left(at\right)$ you take the second derivative of .
Therefore $L\lbrace 5t^{2}\sinh\!\left(at\right)+7t^{2}\sin\!\left(at\right)\rbrace (s) =$ .

Your overall score for this problem is