Question

help!

Answer 1

A watering can dispenses water at a rate of 0.35 gallon per minute. The original volume of water in the can was 9 gallons. Which set of ordered pairs shows the volume of water in the can in gallons (y) as a function of time in minutes (x) from the first minute after the can starts dispensing water?

{(1, 9.0), (2, 8.65), (3, 8.30)}
{(9.0, 1), (8.65, 2), (8.30, 3)}
{(8.65, 1), (8.30, 2), (7.95, 3)}
{(1, 8.65), (2, 8.30), (3, 7.95)}

Answer 2

@legomyego180

Answer 3

hello there! For questions like these, it's helpful to set up a graph to have a better idea of what is being asked

Answer 4

i dont have a graph, sorry , its just a word problem :)

Answer 5

Drawing a graph would help you solve the word problem. So you can have a visual

Answer 6

Do you follow me so far?

Answer 7

ok

Answer 8

based from what the problem gives us, we would have a graph like this. Make sense so far?

Answer 9

yes..

Answer 10

So keep in mind the words that are used in this problem
"The original volume was 9 gallons"

So this means that since volume is represented by y (in gallons), y would equal 9 where x would equal zero.
^^
If this is true, what is the first coordinate?

Answer 11

Hint:

Answer 12

9.0,1?

Answer 13

no no, we're not quite there yet.

The bullet point that I have singled out is (0,9).
So based from this, we know that the next bullet point will look like (1, ?)
We need to find the y point.

Answer 14

oh ok...

Answer 15

But keep in mind, we have a y-intercept now. Based from the graph that I drew, do you know what it is?

Answer 16

um,, no not really..

Answer 17

hmm... have I lost you?

Here. I'll put this nice and simply.

Answer 18

For this problem, we want to find an equation that we can graph and calculate values afterwards in order to solve

Answer 19

So the problem gives us two values:

**a rate of 0.35 gallons/hour
**starting amount of 9 gallons

We can use these numbers to make an equation!
Our equation would be in slope-intercept form (y=mx+b)

Answer 20

I will tell you right now that one of these numbers is the slope, and the other is the y-intercept.

Hint: slopes are RATES.

Answer 21

um, 0,9?

Answer 22

0.35?

Answer 23

Here, I'll tell you. Since the problem is telling us that 9 is the starting amount, the graph will start at y=9. Therefore, that number is the y intercept.

then this means that 0.35 is the slope. HOWEVER, since it is decreasing, this means the slope is negative.

so if the y-intercept is 9 and the slope is -0.35, can you form the equation for me?

Answer 24

(9=0.35+b)?

Answer 25

ah, close! Actually, it would be y=-0.35x+9

Remember, an equation always begins with y=________
and you forgot the negative. But nice attempt!

I really hope this is starting to make a little more sense. Now, do you have a graphing calculator?

Answer 26

ohh ok..

Answer 27

no i dont..

Answer 28

just a regular calculator then?

Answer 29

* do you have a regular calculator?

Answer 30

yes!

Answer 31

ah, okay! Just making sure, very sorry.

So with this equation, y=-0.35x+9, we can plug in numbers to find our points

Answer 32

so try putting this into your calculator:

-0.35(x1)+9 and tell me what you get

Answer 33

ok!!

Answer 34

−0.35x+9

Answer 35

Actually, I want you to multiply -0.35 by 1, then add 9

Answer 36

you should get 1 number, and it will give you the answer

Answer 37

ok..

Answer 38

8.65?

Answer 39

by the way, when a number is in parentheses ( ), it means that you multiply it.


the problem is asking us to look for x values 1, 2, and 3. So we would be doing the following math equations:

-0.35(1)+9
-0.35(2)+9
-0.35(3)+9

if you solve all these, you will get your answers

Answer 40

and yes! that is correct

Answer 41

8.3 and 7.95

Answer 42

yes! So what would the answer be?

Answer 43

D!???

Answer 44

YEP!

Answer 45

Nice job! Does all the work that I did make sense?

Answer 46

or c?

Answer 47

no, it is most definitely D

Answer 48

ok because c are the same answers just backwards..
like..
1,8.65 and d is like.. 8.65,1

Answer 49

oh wait no sorry lol its D.. :) dont listen to me i got cinfused.. lol

Answer 50

remember, ordered pairs go like this:

(x,y)

if the first point is (9,0), then the rest are going to be (8.65,1) and so on and so forth

Answer 51

it's fine, I'm here to clear up any confusion

Answer 52

ok i just have one more question!!