Question

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

Answer 1

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 + 2x

We 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 + 2x

Subtract (2) from (1) to get:

27 = 12g  <= isolate g

g = 27/12

g = 9/4

Substitute g = 9/4 in (2)

22 = 8g + 2x

22 = 8(9/4) + 2x

Now simplify and isolate x.

22 = 18 + 2x

2x = 4

x = 2

x represents one quart of oil.

Therefore, one quart of oil is $2.