Answer: A
Step-by-step explanation:
The equation representing thiis scenario is expressed as
x + 30y = 450
where
x represents the number of miles
y represents the remaining gallon of gas in the tank.
From the equation, we would subtract x from both sides, it becomes
x - x + 30y = - x + 450
30y = - x + 450
Dividing through both sides by 30, it becomes
30y = - x/30 + 450/30
y = - x/30 + 15
On the !st of february when the gas was put in th tank, the number of miles is zero. Substituting x = 0 into the equation, it becomes
y = - 0/30 + 15
y = 15
Thus, number of gallons of gas that Alex put in his tank on 1st of February is 15