Answer:the cost of 1 gallon of gas is $2.31
the cost of 1 quart of oil is $1.7
Step-by-step explanation:
Let x represent the cost of 1 gallon of gas.
Let y represent the cost of 1 quart of oil.
A motorist paid $26.50 for 10 gallons of gas and 2 quarts of oil. It means that
10x + 2y = 26.5 - - - - - - - -1
Another motorist paid $23.58 for 8 gallons of gas and 3 quarts of oil. This means that
8x + 3y = 23.58 - - - - - - -- - - - 2
Multiplying equation 1 by 3 and equation 2 by 2, it becomes
30x + 6y = 79.5
16x + 6y = 47.16
Subtracting, it becomes
14x = 32.34
x = 32.34/14 = 2.31
Substituting x = 2.31 into equation 1, it becomes
10 ×2.31 + 2y = 26.5
23.1 + 2y = 26.5
2y = 26.5 - 23.1 = 3.4
y = 3.4/2 = 1.7
