In Niagara-on-the-Lake, you can ride a horse-drawn carriage for a fixed price plus a variable amount that depends on the length of the trip. The variable cost is $10/km and a 2.5-km trip costs $40. a) Determine the equation relating cost, C, in dollars, and distance, d, in kilometres. b) Use your equation to find the cost of a 6.5-km ride. c) Graph this relation. d) Use the graph to find the cost of a 6.5-km ride.

Step-by-step explanation:

a) The cost of a product is given as:

Cost = a + bx

Where a is the fixed cost, b is the variable cost, x is the independent variable.

In this case, the independent variable is the distance(d), therefore:

Cost (C) = a + bd

C = a + bd

But the variable cost is $10/km, therefore:

C = a + 10d

A 2.5 km trip cost $40, therefore:

40 = a + 10(2.5)

40 = a + 25

a = 40 - 25 = 15

The fixed cost is $15. Therefore the equation for cost is:

C = 15 + 10d  

b) C = 15 + 10d  

For 6.5 km ride:

C = 15 + 10(6.5) = 15 + 65 = 80

It would cost $80 for a 6.5 km drive.