algebra
posted by PLEASE NEED HELP on .
Finances. During one month, a homeowner used 500 units of electricity and 100 units of gas for a total cost of $352. The next month, 400 units of electricity and 150 units of gas were used for a total cost of $304. Find the cost per unit of gas. Please show the work. Thanks

Two equations; two unknowns.
500 x + 100 y = 352
400 x + 150 y = 304.
Solve for x and y.
y is the cost per unit of gas.
x is the cost per unit of electricity.
2000 x + 750 y = 1520
2000 x + 400 y = 1408
350 y = 112
y = $0.32 per unit
x = $0.64 per unit