Problema Solution
During one month, a homeowner used 600 units of electricity and 100 units of gas for a total cost of $404. The next month, 400 units of electricity and 250 units of gas were used for a total cost of $339. Find the cost per unit of gas.
Answer provided by our tutors
Let
x = the cost per unit of electricity
y = the cost per unit of gas
During one month, a homeowner used 600 units of electricity and 100 units of gas for a total cost of $404:
600x + 100y = 404
The next month, 400 units of electricity and 250 units of gas were used for a total cost of $339:
400x + 250y = 339
We have the following system of equations:
600x + 100y = 404
400x + 250y = 339
........
........
x = $0.61
y = $0.38
The cost of gas is $0.38 per unit.