Negation of the inverse of the following statement pattern $(p \wedge q) \rightarrow (p \vee \sim q)$ is

$\sim (p \vee (\sim q))$ is equal to .......

Let $p$ be the statement '$x$ is an irrational number',$q$ be the statement '$y$ is a transcendental number',and $r$ be the statement '$x$ is a rational number or $y$ is a transcendental number'.
Statement-$1$: $r$ is equivalent to $q \lor p$.
Statement-$2$: $r$ is equivalent to $(p \Leftrightarrow \sim q)$.

The contrapositive of the statement,"If two lines do not intersect in the same plane,then they are parallel," is:

Which of the following sentences are statements? Give reasons for your answer.
Mathematics is difficult.

Write the negation of the following statement and check whether the resulting statement is true:
The sum of $3$ and $4$ is $9.$