Question

In the last race , the first car in the pit used 1 3/4 tanks of gas, the second car used 2 1/8 and the third car used 1 1/2 tanks of gas. what was the total positive or negitive change in the amount of gas for all three cars

Answer 1

Answer:
`-5(3)/(8)` tanks of gas

Explanation:

Let the x be the number of tanks of gas, then

The amount of gas used by first car=
`1(3)/(4)x=(7)/(4)x`

The amount of gas used by second car=
`2(1)/(8)x=(17)/(8)x`

The amount of gas used by third car=
`1(1)/(2)x=(3)/(2)x`

Thus, the total change in the amount of gas for all three cars=
`(7)/(4)x+(17)/(8)x+(3)/(2)x`

`=x((7)/(4)+(17)/(8)+(3)/(2))\\\\=x((14+17+12)/(8))\\\\=x((43)/(8))\\=5(3)/(8)x`

Since, the amount of gas
`5(3)/(8)` tanks of gas is used for all three cars.

Therefore, the total amount would be negative .

hence, the answer is
`-5(3)/(8)` tanks of gas.