Question 252699
Let the cost function be:
(i) C = mP + b
Where C = total cost, P = number of people, b = fixed cost, and m = cost per person.
we actually have coordinates: (100,750) and (150,1050). We put those into (i).
(ii) 750 = 100m + b
(iii) 1050 = 150m + b.
At this point, multiply (ii) by -1 and add down.
(iv) 300 = 50m
m = 6: Cost per student
Now we put 6 back into (ii) for m to find b.
(v) 750 = 100(6) + b
b = 150: fixed cost
C = 6P + 150.