Question

A caterer charges $275 for 15 people and $425 for 25 people. The cost, y, is a

linear function of the number of people. Write an equation in slope-intercept
form for this situation.

Answer 1

y = 15x + 50

Explanation:

We set out by finding the slope

the two points give are (15,275) and (25,425)

Slope m is;

y2-y1/x2-x1 = (425-275)/25-15 = 150/10 = 15

So the equation is like;

y = 15x + b

To get b, let us use the point (15,275)

We have

275 = 15(15) + b

b = 275-225

b = 50

So the equation is;

y = 15x + 50