Answer:
15x because the air ballon drops 15 meters each time the elevation decreases
Step-by-step explanation: Im not sure if this is what youre looking for but it drops 15 meters each time, 5 times so the change would be 15x and the x is used as how mant different times the elevation drops
Let x = discount rate
Equate:
$80(1-x) = $60
Solve for x:
1-x = 60/80
1-x = 3/4
x = 1 - 3/4
x = 1/4 or 0.25
x = 25%
X Times x is x^2
X^2-8x+3x-24
x^2-5x-24
Slope:5
Intercept:5
Hope I helped