Question

fiona is serving ice cream and lemonade at a picnic. she has 44 cups in which to serve the drinks . if X represents the number of glasses of iced tea and y represents the number of glasses of lemonade.

Answer 1

We should find out the equation that represents the number of drinks Fiona can serve. We know X as the number of glasses of iced tea and Y as the number of glasses of lemonade. 
Fiona can serve both of them. She has 44 cups.
The equation is:
X+Y=44
the constraint is: X and Y must be positive numbers.