SOLUTION: Company C uses a linear relationship and for 100 miles a day the rental cost is $50, while if you drive 400 miles a day the cost is $68. What is the formula?

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Company C uses a linear relationship and for 100 miles a day the rental cost is $50, while if you drive 400 miles a day the cost is $68. What is the formula?      Log On


   

Question 713507: Company C uses a linear relationship and for 100 miles a day the rental cost is $50, while if you drive 400 miles a day the cost is $68. What is the formula?
Answer by josgarithmetic(39799) About Me  (Show Source):
You can put this solution on YOUR website!
Assign those numbers to an arrangement of (x,y) coordinates; TWO of them.

Do as x for miles and y for cost. The points are (100, 50) and (400, 68). Two points - Find the linear equation.

Slope, m=(68-50)/(400-100)
m=18/300, m=3%2F50

Point-Slope Form For a Line: y-y%5B0%5D=m%28x-x%5B0%5D%29. Substitute for m, Pick either of the data points for (x%5B0%5D,y%5B0%5D). Simplify.