Answer:
y = 1.5x + 9
(y = height; x = number of cups)
Step-by-step explanation:
let x = number of cups
let y = height of the stack
the first cup will add 9 to the height (7.5 + 1.5)
so 9 is the y-intercept
for each additional cup, 1.5 will be added
so y = 1.5x + 9
