Consider the following predicates over the domains $B$ of all bunny rabbits, $M$ of all magicians, and $J$ of all jazz musicians.
$F(x; y)$: person $x$ sent a friend request to person $y$.
$D(x; y): x$ made $y$ disappear.
$H(x; y): x$ enjoys being made to disappear by $y$.
a) $\forall a\in B\ \neg(\exists c\in B\ a\ne c\land D(a,c))\iff\forall b\in M\ H(a,b)$
I have: every bunny rabbit cannot make some other bunny rabbits disappear if and only if every bunny rabbit enjoys being made to disappear by magicians.
Not sure if this is right because I'm having a little trouble translating $\lnot (\exists c \in B, a \neq c \land D(a,c))$ into English.
The best way to approach these problems is to literally say them out: $$\forall a\in B\ \neg(\exists c\in B\ a\ne c\land D(a,c))\iff\forall b\in M\ H(a,b)$$
Then simplify: