Question

. Each household in the town of Maple Grove receives a water bill each month. Their bill consists of a fixed charge plus a charge for each cubic foot of water that they use. Suppose that a household that used 1000 cubic feet was billed $40 for the month, while one using 1600 cubic feet was billed $55. A household that used 2400 cubic feet would be charged

Answer 1

Answer: A household that used 2400 cubic feet would be charged $75

Step-by-step explanation:

Their bill consists of a fixed charge plus a charge for each cubic foot of water that they use.

Let x represent the value of the fixed charge in $

Let y represent the amount charged per cubic foot of water used.

Suppose that a household that used 1000 cubic feet was billed $40 for the month. This means that

x + 1000y = 40 - - - - - - - - - -1

Another household using 1600 cubic feet was billed $55. This means that

x + 1600y = 55 - - - - - - - - -2

Subtracting equation 2 from equation 1, it becomes

- 600y = - 15

y = - 15/-600

y = 0.025

Substituting y = 0.025 into equation 1, it becomes

x + 1000×0.025 = 40

x + 25 = 40

x = 40-25 =15

If a household that used 2400 cubic feet, the amount charged would be

15 + 2400×0.025 = 15 + 60 = $75