Drinks sold: 29
X=small drink $.35
y= Large drink $8.50
x+y=$13.45

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.