Karina uses the system of equations below to compare the monthly utility costs in July and December for electricity, x, and natural gas, y. 750x + 17y = 141.61300x + 30y = 75.90
A
The cost of natural gas is $0.17 per unit.B
The cost of natural gas is $0.20 per unit.C
The cost of natural gas is $0.72 per unit.D
The cost of natural gas is $0.83 per unit.