There were 20 gallons of gasoline in your car's gas tank. you used 4 gallons and 1 quart. how much gasoline remains in the tank?

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,