A bathtub contains 25 gallons of water. The tub is draining at a rate of 4.5 gallons per minute. Write a function

Question

i don't know. i don't understand the question, and I need to do it for my test tomorrow

Answer 1

The problem says the tank has 25 gallons of water . The tub is draining at a constant rate of 4.5 gallons of water.

Now let the time be our variable x and the amount of water in the tank at any time be the variable y.

x and y are connected by a linear equation, since the rate is constant.

at time x=0, there was 25 gallons of water so, we have an ordered pair ( a coordinate point ( x,y = ( 0, 25))

The rate gives the slope of a line so m =- 4.5 since it is draining, it is negative.

 

we say y is a function of x.

Here the function is y =mx+b ( I hope you are familiar with this). So, y is dependent on x, and we can write y =f(x); this is read as "y is a function of x"

Our function is f(x) = mx+b

 

f(x) = -4.5x+25

Answer 2

A function relates an input to an output & is expressed as f(x) = 

 

So for this example f(x)= 25-4.5x because you will be losing 4.5 gallons of the 25 total gallong of water for every minute that goes by.