Which if the following relations represent functions?

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?

What is the value of x in the equation7x+2y=48 when y=3

Hormones perform important functions within the reproductive system. during puberty, a number of changes occur in the body. which hormone is responsible for the development of these characteristics in the female? estrogen progestin progesterone testosterone