The amount of water in a bathtub as it drains can be modeled by this equation with y representing the number of gallons of water in the tub and x representing the time, in minutes, that the tub has been draining. y=−7.3x+39.7 after how many minutes will the tub have 17.8 gallons of water remaining? enter your answer in the box. min

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.