Determine weather each relation is a function

(5,12), (-4,9), (-2,-7), (-4,0), (3,2)

Sara can take no more than 22 pounds of luggage on a trip.her suitcase weighs 112 ounces.how many more pounds can she pack without going over the limit?

Savannah is painting a striped background for a mural on a wall that is 1515 yards long. she wants a total of 9696 stripes that are all the same width. which calculation should savannah use to decide how wide to make each stripe?

How do i multiply two digit numbers