Question 251757
To solve this you may need a tautology table, or memorize it.

P big space Q big space P->Q big space PvQ
T big space T big space     T      big space    T
T big space F big space     F      big space    T
F big space T big space     T      big space    T
F big space F big space     T      big space    F

Now, P->Q  {T, F, T, T}

(P->Q) -> Q {T, T, T, F}

(P->Q) -> Q -> (PvQ) { T, T, T, T}

A bit tough to follow I think, but there it is.