Answer
a) 1
b) 1
c) 1
d) 0
Work Step by Step
Before starting the problem, consider the domain, all integers.
a) $\forall n(n+1>n)$ is true because $1=n+1-n>n-n=0$ always holds.
b) $\exists n(2n=3n)$ is true because $2(0)=3(0)$, and 0 is an integer.
c) $\exists n(n=-n)$ is also true when $n=0$.
d) A counterexample to the statement $\forall n(3n\leq 4n)$ is $n=1$, so the statement is not true.
