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Explanation:
Let x be the number of gallons used up. It's some positive real number.
We'll use the formula
miles = (mpg)*(number of gallons)
to help figure out how much fuel is used. The trip is 432 miles, and the mpg rating is 31
So,
miles = (mpg)*(number of gallons)
432 = 31*x
31x = 432
x = 432/31
x = 13.9354838709678 which is approximate.
Multiply that with the 2.79 to get the final answer.
2.79*x = 2.79*13.9354838709678 = 38.8800000000001
The 1 at the very end is probably due to some rounding error, but then again it may be accurate. Either way, that value rounds to 38.88
Side note: The 31 mpg rating is very likely an average value and not the same throughout the trip. This is due to the car changing speeds at different points of the journey. In reality, the true answer will vary slightly from the 38.88 figure we just calculated (but it should be fairly close).
The total amount of money that Tom and his friend would spend on gas during the trip is $38.88.
The first step is to determine the total amount of gas that would be needed during the trip.
Gas that would be needed = 432 / 31 = 13.94
The second step is to multiply the gas that would be needed by the cost of gasoline: $2.79 x 13.94= $38.88
To learn more about multiplication, please check: https://brainly.com/question/3385014