How and what are they :/ plz help

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Two angles are complementary. the large angle is 36 more than the smaller angle. what is the measure of the large angle?

Campus rentals rents 2 and 3 bedrooms apartments for $700 ans $900 a month respectively. last month they had six vacant apartments and reported $4600 in lost rent. how many of each type of apartment were vacant?