SOLUTION: During one month, a homeowner used 300 units of electricity and 130 units of gas for a total cost of $110.30. The next month, 220 units of electricity and 250 units of gas were use

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Question 1050529: During one month, a homeowner used 300 units of electricity and 130 units of gas for a total cost of $110.30. The next month, 220 units of electricity and 250 units of gas were used for a total cost of $97.90. Find the cost per unit of gas.
Answer by advanced_Learner(501) About Me  (Show Source):
You can put this solution on YOUR website!
300x+130y=110.30
220x+250y=97.90
Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
We'll use substitution. After moving 130*y to the right, we get:
300%2Ax+=+110.3+-+130%2Ay, or x+=+110.3%2F300+-+130%2Ay%2F300. Substitute that
into another equation:
220%2A%28110.3%2F300+-+130%2Ay%2F300%29+%2B+250%5Cy+=+97.9 and simplify: So, we know that y=0.11. Since x+=+110.3%2F300+-+130%2Ay%2F300, x=0.32.

Answer: system%28+x=0.32%2C+y=0.11+%29.