Question

The cost for 25 square yards of carpet is $650 including delivery and installation. The cost for 40 square yards of installed carpet is $950. Write an equation in slope-intercept form (y = mx + b) for the cost of the installed carpet

Answer 1

The equation is;

y = 20x + 150

Explanation:

Firstly, let us identify the coordinates

(area, cost of area)

We start by getting the points;

(25,650) and (40,950)

The slope will be;

m = (y2-y2)/(x2-x1)

m = (950-650)/(40-25)

m = 300/15 = 20

So the partial equation is;

y = 20x + c

To get the value of c which is the y-intercept, we make use of any of the two points

650 = 20(25) + c

650 = 500 + c

c = 650-500

c = 150