Question

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 = 141.61
300x + 30y = 75.90
Karina solves the system using linear combination and arrives at the equation 116y = 96.28. She then solves this equation for y. Which statement explains Karina’s solution?

a. The cost of electricity is $0.17 per unit.
b. The cost of natural gas is $0.20 per unit.
c. The cost of electricity is $0.72 per unit.
d. The cost of natural gas is $0.83 per unit.

Answer 1

@cj49

Answer 2

116y=96.28
y=96.28/116=0.83

Answer 3

wait...
multiply the first equation by 30 and the second by 17 and then subtract 1 from 2
22500x+510y=4248.3
51500x+510y=2958
ull gt x=0.17 and y=0.83