Answer:
After 3 minutes the tub will have 17.8 gallons of water remaining.
Step-by-step explanation:
Given : The amount of water in a bathtub as it drains can be modeled by the equation,
y = −7.3 x + 39.7 .............(1)
Where, y representing the number of gallons of water in the tub and x representing the time, in minutes.
We have to determine the time when the tub have 17.8 gallons of water remaining.
That is y = 17.8
Substitute y = 17.8 in (1) , we get,
⇒ y = −7.3 x + 39.7
⇒ 17.8 = −7.3 x + 39.7
Solve for x , we get,
⇒ 17.8 - 39.7 = −7.3 x
⇒ - 21.9 = −7.3 x
⇒ 21.9 = 7.3 x
⇒ x = 3
Thus, after 3 minutes the tub will have 17.8 gallons of water remaining.
