Answer:
Step-by-step explanation:
y = 25x +100
y- is the total money spent on the phone
x-is the number of months you had service
the relationship between x and y is proportional ( if x grows, y grows)
For example: after 2 months you would had payed $100 for the phone + the $25 each of the 2 months. y= 25*2 +100 = $150
