How to do this question ? This is simply an exercise from a lecture that I didn't get my prof solving it

2. a) Rewrite the proposition \"VA Q (Q, VB Q Q, ((A Q B) A (B Q A)) => (A = B)\" in an equivalent contrapositive form that does not contain the logical connective \"\".~ b) Rewrite \"The difference of the squares of any two integers is always equal to the cube of some real number\" in an equivalent form that uses variables and that contain the two quantiers \"V\" and \"El\". c) Rewrite the proposition \"~ (Vm E Z, ((Iml (Elp E R434 2m 5 7D)\" in an equivalent form at 7) that contains none of the logical connectives ~ and \"=>\