Hey there!
Let "x" the number of gallons and "y" by the distance travelled.
According to question,
12x + 288y = 0 -->(i) x + 192y = 0
=> 12(x + 192y) = 0 × 12
=> 12x + 2304y = 0 -->(ii)
By Elimination method,
Equation (i) - (ii)
(12x + 288y) - (12x + 2304y) = 0 - 0
=> 12x + 288y - 12x - 2304y = 0
=> - 2016y = 0
=> y = 2016
Putting the value of "y" in Equation (i)
12x + 288y = 0
=> 12x + 288 × 2016 = 0
=> 12x + 580608 = 0
=> 12x = - 580608
=> x = 48384
Hope it helps
