<PRE><B>Question 1137792</B>
During one month, a homeowner used 700 units of electricity and 100 units of gas for a total cost of $416. The next month, 500 units of electricity and 250 units of gas were used for a total cost of $365. Find the cost per unit of gas.
solution let cost of electricity x and gas is y per unit
700x+100y=416   (1)
500x+250y= 365   (2)    by multiplying  5 first and 2 to second equation
3500x +500y= 2080
1000x+500y=  730  by solving elimination method 
 2500x= 1350
X=$0.54  per unit   similarly   270+250y= 365    250y=  95     y=  $ 0.38 per unit 
answer $0.38 per unit gas cost


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