SOLUTION:
During one month, a homeowner used 200 units of electricity and 130 units of gas for a total cost of $81.60. The next month, 220 units of electricity and 200 units of gas were us
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During one month, a homeowner used 200 units of electricity and 130 units of gas for a total cost of $81.60. The next month, 220 units of electricity and 200 units of gas were us
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Question 712065:
During one month, a homeowner used 200 units of electricity and 130 units of gas for a total cost of $81.60. The next month, 220 units of electricity and 200 units of gas were used for a total cost of $96.60. Find the cost per unit of gas. Answer by checkley79(3341) (Show Source):
You can put this solution on YOUR website! 200X+130Y=81.60 MULTIPLY BY -1.1 & ADD.
220X+200Y=96.60
-220X-143Y=-89.76
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57Y=6.84
Y=6.84/57
Y=$.12 PER UNIT OF GAS.
200X+130*.12=81.60
200X+15.6=81.60
200X=81.60-15.6
200X=66
C=66/200
X=$.33 PER UNIT OF ELECTRICITY.
PROOF:
220*.33+200*.12=96.60
72.60+24=96.60
96.60=96.60
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