Question

Need help writing an equation:
A TANK IS FILLING WITH WATER FROM A NATURAL SPRING. TWO DAYS AGO THE WATER WAS 10 FEET DEPTH, AND YESTERDAY THE WATER WAS 12 FEET. ASSUME THAT THE WATER DEPTH CONTINUES TO RISE AT THIS RATE AFTER TODAY.

Answer 1

the slope is 2 thats what I already know and im sure :)

Answer 2

x+2
let x be the day

Answer 3

am i rite!!!

Answer 4

?

Answer 5

which is y=mx+b
right?

Answer 6

what coordinates do you use?

Answer 7

so -2=2(2)+b
is the 2 in parenthesis be a negative or positive

Answer 8

what am I suppose to do??????????????

Answer 9

No

Answer 10

whats a whats d

Answer 11

help me im confused

Answer 12

I SERIUOSLY NEED HELP CAN YOU JUST SHOW MW HOW TO FIND THE ANSWER!
I LEARN FROM THE WORK

Answer 13

SO YOU DISTRIBUTE RIGHT

Answer 14

so the equation is y=2n+12

Answer 15

I keep putting that in the answer and it says Im wrong

Answer 16

hmm i think it would be y = 2x+14 since Today the water level is 14

Answer 17

Let me try that kay?

Answer 18

nope its wrong

Answer 19

or using point slope form:
point (-1,12)
slope = 2

y-12 = 2(x-(-1))
y -12 = 2x +2
y = 2x +14

Answer 20

l=2d+10. l= water level and d= days

Answer 21

ikr

Answer 22

?

Answer 23

Want an explanation?

Answer 24

NO THANKS

Answer 25

k, once someone ahelps you with the problem the answer will be l=2d+10. l= water level and d= days ;)

Answer 26

10,12,14 ...

the rate is increase of 2 per day
so the equation is:
y = 2x +b

to know "b" we need what day is the starting point
i was assuming x=0 meant TODAY
is there more info in the problem ?

Answer 27

sorry wait tO FIND b IN Y=2X+B YOU CAN SUBSTITUTE IN ONE OF THE COORDINATES PAIRS -2 for x and 10for y. for example you can substitute -2 for x and 10 for y. this gives 10=(2)(-2)+b. solve this equation for b and substitue that value for in to the expression

Answer 28

that what that says

Answer 29

I didn't follow all the conversations.
Now that we should be able to make a rule, what is the question?
I.e. what are we required to find?

Answer 30

We need the water level today?

Answer 31

or the rule?

Answer 32

an equation

Answer 33

ill atach the question so you can see it okay?

Answer 34

Like dc mentioned, it depends on where we take x=0.
The rule (equation) is different if we take x=0 as today, yesterday or the day before.
So there are three possibilities. How many have you already tried?

Answer 35

this is the question

Answer 36

It is much simpler if you post the question, because in the question it says
"Time elapsed from today" which means that today is the same as x=0.
The complete question is:

A TANK IS FILLING WITH WATER FROM A NATURAL SPRING. TWO DAYS AGO THE WATER WAS 10 FEET DEPTH, AND YESTERDAY THE WATER WAS 12 FEET. ASSUME THAT THE WATER DEPTH CONTINUES TO RISE AT THIS RATE AFTER TODAY.
1. When will the water be 14 feet deep?
2. How long will the water tale to reach a depth of 50 feet?
3. How deep will the water in the tank be in 21 days?
4. How deep was the water in the tank three days ago?
Time elapsed from today The depth of the water in the tank
Unit: days Unit: feet
Expression: x Expression: IDK
Question 1: Question 1: 14
Question2: Question2: 50
Question3: 21 Question3:
Question 4: -3 Question 4:

We will answer them one by one.

Answer 37

THE EQAUTION IS JUST 2X+14 NO Y= 'S

Answer 38

If you make a table, x=days from today, H=height
x H
-2 10
-1 12
So the rate of increase is 2 feet per day, so today, the height is 14.
The rule is therefore H=2x+14 (today is day zero)

Is that ok so far?

Answer 39

An equation always needs an equal sign. If you say the rule, it could be 2x+14 (with height being understood).

Answer 40

For questions 2, 3 and 4, you need to substitute the known values of x (or H) into the equation, and solve for the other variable.
For example, if it asks "when will the water level be 26 feet high", then put H=26 into the above equation ans solve for x (days from today):
26=2x+14 => 26-14=2x+14-14 => 2x=12 => x=6
So 6 days from now, the water level will be 26 feet high. etc.

Answer 41

I got it thanks

Answer 42

yw! :)

Answer 43

Gave you a medal for your hard work mathmate.

Answer 44

Thank's a million! :)