Answer:the number of gallons of gas that Mr Lewis's car hold is 12.125 gallons
Step-by-step explanation:
Let x represent the number of gallons of gas that Mr Lewis's car hold.
Mr.Lewis filled up his cars gas tank completely on Monday. Between Monday and Friday, Mr.Lewis's car used up to 6 3/8 gallons of gas. Converting 6 3/8 to improper fraction, it becomes 51/8 gallons of gas.
Amount of gas left would be
x - 51/8
On Saturday, Mr.Lewis adds 4 3/4 gallons of gas to his car gas tank. Converting 4 3/4 to improper fraction, it becomes 19/4 gallons.
Total amount left would be
x - 51/8 + 19/4
After he added more gas to the gas tank, the gas tank contained 10 1/2 gallons of gas. Converting 10 1/2 to improper fraction, it becomes 21/2 gallons. Therefore
x - 51/8 + 19/4 = 21/2
Multiplying both sides of the equation by 8, it becomes
8x - 51 + 38 = 84
8x - 13 = 84
8x = 84 + 13 = 97
x = 97/8 = 12.125
