SOLUTION: How many gallons of 94-octane gasoline should be mixed with 400 gallons of 99-octane gasoline to obtain a mixture that is 97-octane?

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Question 157314: How many gallons of 94-octane gasoline should be mixed with 400 gallons of 99-octane gasoline to obtain a mixture that is 97-octane?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
.94x+.99*400=.97(400+x)
.94x+396=388+.97x
.94x-.97x=388-396
-.03x=-8
x=-8/-.03
x=266.67 gallons of 94% octane is needed.
Proof:
.94*266.67+.99*400=.97(400+266.67)
250.68+396=.97*666.67
646.67=646.67