18) In this problem they are telling you that the cost of the gifts are given by the equation:

So to know the cost of each gift we can solve for g so:

So he has 25 gifts for each gift. So is B.
19) now the expression that represent the number of games is:

So the correct expression is:
A) Lori owns 3 less games than 4 times the number of games that have nathan.