Chang and cal both collect pearls. chang has three more pearls in her collection than cal. write an expression to represent the total number of pearls in both collections.

Let x be the number of pearls in Chang's collection.  Let y be the number of pearls in Cal's collection.

Chang has 3 more than Cal, so x = y + 3.
Adding both collections would be x + y.  It's easier to have an expression in one variable, so we will substitute what we had written about Chang in for x.
(y + 3) + y = 2y + 3.

40 because it’s just a little longer than 32 feet