In a family there are two cars. In a given week, the first car gets an average of 35 miles per gallon, and the second car gets 25 miles per gallon. The two cars combined drive a total of 1750 miles in that week, for a total gas consumption of 60 gallons. How many gallons were consumed by each of the two cars that week?
2007-02-20 17:30:58 · 2 answers · asked by jenni_sox 1 in Science & Mathematics ➔ Mathematics
x=the first car gallon spent
y= the second car gallon spent
35x+25y=1750
x+y=60
Hence by subtracting
35x+25y=1750
25x+25y=1500
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10x=250
x=25 gallons
y=60-25=35 gallons
2007-02-20 18:03:36 · answer #1 · answered by iyiogrenci 6 · 0⤊ 0⤋
let x be the amount of gallons consumed by the first car.
let y be the amount of gallons consumed by the second car.
35x + 25y = 1750 --- (1)
x + y = 60 --- (2)
solving for x and y (substitute (2) into (1)):
35 (60-y) + 25y =1750
2100 - 35y + 25y = 1750
-10y = -350
y = 35
substitute y = 35 into (2):
x + 35 = 60
x = 25
2007-02-21 02:04:50 · answer #2 · answered by sirius 2 · 0⤊ 0⤋