Answer
See below.
Work Step by Step
The negation of $ p\rightarrow q$ is $p\land \sim q$.
De Morgan's Laws says that $\sim (p\land q)\equiv \sim p\lor \sim q$ and $\sim (p\lor q)\equiv \sim p\land \sim q$.
Thus here the negation is: $p\land \sim(r\land \sim s)\equiv p\land (\sim r \lor s)$
