Question

At time x=​0, water begins to drip steadily out of a water tank. After 3 hours ​, there are 6.8 gallons of water in the tank. After 9 ​hours, 4.4 gallons remain. Write a linear function rule that models the number of gallons of water y left in the tank for any number of hours x. The linear function rule is y = ___

Answer 1

Answer:

$y=-0.4x+8$

Step-by-step explanation:

Let the Linear Function to represent the drip of water out of the water tank be:

$y=mx+c$

Where $x$ is the time

$y$ is the number of gallons at that time

$m$ is the rate at which water drips

$c$ is the initial number of gallons of water in the tank

Putting the given values in the above equation:

$6.8 = m\times 3+c ..... (1)$

$4.4 =m\times 9+c..... (2)$

Subtracting (1) from (2):

$6m=-2.4\\\Rightarrow m =-0.4$

Putting in equation (1):

$6.8=-0.4\times 3+c\\\Rightarrow c = 8$

Therefore, the linear function equation to represent in the situation is:

$y=-0.4x+8$