Question

Explain, in complete sentences, how you would use the graphing method to solve the following system of equations and what the final solution will look like on the coordinate plane.
x + y alt= -6
2x - 3y < 0

Answer 1

I've not seen y alt before. Can you tell me what it means?

Answer 2

oh its suppose to mean greaterthan or equal too . sorry :/

Answer 3

ok

Answer 4

Well you graph each of the lines. DO you know how to do that?

Answer 5

nope i dont know how to do that .

Answer 6

To graph x +y =-6 you need to find some points that make it true and then join them up with a line. So if x = 0, what will y = to make it true?

Answer 7

-6 ?

Answer 8

yes.
So one co-ordinate will be (0,-6)
If y = 0, what will x be?

Answer 9

would it still be -6 ?

Answer 10

Yes
So another point to plot will be (-6,0). Can you draw that on a graph?

Answer 11

It should look a bit like this

Answer 12

With the other equation it might be best to rearrange it in the form y=...

Answer 13

y = mx+b ?

Answer 14

yup. Can you do that?

Answer 15

i can but i dont really remember how to do it .

Answer 16

2x-3y=0
add 3y to both sides gives you...

Answer 17

2x=3

Answer 18

oops - lost the y
should be 2x=3y

Answer 19

ohh , my bad

Answer 20

Now we want the y without the 3 so what do we do to get rid of it?

Answer 21

-3

Answer 22

nope sorry
3 y means 3 times y so we have to do the opposite of multiplying to get rid of it.
So what should we do?

Answer 23

wouldnt you multiply the 3y by 2 for it to equal 6y and do 2x multiply by -3 for it to equal -6 and it cancels out ?

Answer 24

Whatever you do to one side you have to do to the other side.
If you multiply by 2 you will get
4x=6y
What you need to do is divide by 3 to get rid of it.
Then you will have 2/3x=y

Answer 25

oh okayyy

Answer 26

So your two lines graphed should look a bit like this
y=2/3x
can you graph it?

Answer 27

Are you still there?

Answer 28

yeah sorry my computer froze

Answer 29

So can you graph the two lines now or do you need a bit more help with that bit?

Answer 30

a need help . i tried doing it but im just confused

Answer 31

in the first one you plotted the two points, (0,-6) and (-6,0) and joined them up.
is that ok?

Answer 32

yahh thats okay

Answer 33

Great
Then in the second one, we can use the y=mx+c method.
y= 2/3x
What is m?
What is c?

Answer 34

i dont know what it is

Answer 35

Where are you, by the way? What country?

Answer 36

m is the slope. In this equation it is 2/3
c is the intercept. In this equation it is 0.
Is that at all familiar?