Question

A bus company took a tour bus on the ferry when there were 30 people aboard. The ferrycharged the bus company $180. The following week, the bus had 50 people on board and theferry charged them $220. Write an equation in slope-intercept form the represent thissituation. How much does it cost per person?

Answer 1

Slope intercept form

y=mx+b

Where:

m= slope (cost per person)

b= y-intercept

people already aboard = 30

x= number of people

If x=30 y=180

if x=50 y= 220

180= 30m+b (1)

220= 50m+b (2)

Subtract (1) to (2)

40= 20m

40/20 = m

m= 2

It costs $2 per person.

SO far the equation is:

y= 2x+b

Plug a value of (x,y) and solve for b

For example, we use x=30 and y=180

180=2(30)+b

180 =60+b

180-60=b

120=b

Final equation:

y=2x+120