posted by Jessica on .
A caterer charges a fixed cost for preparing a dinner plus an additional cost for each person served. You know that the cost for 100 students will be $750 and the cost for 150 students will be $1050. Find the caterer's fixed cost and the cost per student served.
Look at it as being given two ordered pairs
(100,750) and (150,1050)
let's find the equation in the form
y = mx + b, (b will be the fixed cost and m the cost per student)
slope = m = (1050-750)/(150-100) = 6
using (100,750) ...
750 = 6(100) = b
b = 150
then y = 6x + 150
(check: if x = 150, y = 6(150) + 150 = 1050 , YEAH
so the fixed cost is $150, cost per student is $6