Q:

You pay $24.50 for 10 gallons of gasoline and onequart of oil at a gas station. Your friend pays $22 for 8gallons of the same gasoline and 2 quarts of the sameoil. Find the cost of l quart of oil.

Accepted Solution

A:
Answer:1 quart of oil is $2.Step-by-step explanation:Represent the problem with equations.let x be a quart of oil and g be a gallon of gasoline(1) 24.5 = 10g + x(2) 22 = 8g + 2xWe need to solve this system of equations to get x.I can solve by elimination by making both equations have 2x.Multiply equation (1) by 2. Equation (2) remains the same.(1) --> 49 = 20g + 2x(2)     22 = 8g + 2xSubtract (2) from (1) to get:27 = 12g  <= isolate gg = 27/12g = 9/4Substitute g = 9/4 in (2)22 = 8g + 2x22 = 8(9/4) + 2xNow simplify and isolate x.22 = 18 + 2x2x = 4x = 2x represents one quart of oil.Therefore, one quart of oil is $2.