Question

PLEASE HELP A hot tub filled with 440 gallons of water is being

drained. After 1.5 hours, the amount of water had

decreased to 320 gallons.

The initial amount of water in the hot tub was

440 gallons, so (0, 440) is on the line.

After 1.5 hours, the amount of water had decreased

to 320 gallons, so (1.5, 320) is on the line.

Answer 1

The slope of the line, m=-80 and

The equation of the line is,
`y=-80+440`

Explanation:

Given that initially the hot tub is filled with 440 gallons of water.

So, at time t=0, the amount of water = 440 gallons.

Further, after 1.5 hours, the amount of water had decreased to 320 gallons.

So, at time t=1.5 hours, the amount of water = 320 gallons.

The point (0,440) and (1.5, 320) are on the line.

So, the slope, m, of the line is

`m=(440-320)/(0-1.5)=-(120)/(1.5)=-80`

The equation of the line is

`y-440=-80(x-0) \\\\\Rightarrow y-440=-80x \\\\\Rightarrow y=-80x+440`

Hence, the slope of the line, m=-80 and the equation of the line is,
`y=-80+440`.