Question

What quadrant are the equations in?

A. 3x + 2y = -15
x - 4y = -20

B. 10x - y = -30
x - y = -2

C. 2x - 5y = 10
x + 2y = 10

D. 3x + y = 9
-7x - 7y = -14

Answer 1

http://lhh.tutor.com/presession.aspx?ProgramGUID=c2f98cc5-be2f-42f3-abbd-891c960a6bd5&TopicId=1&InterfaceId=k12&InterfaceType=k12

Answer 2

go there for some accuarate help

Answer 3

I don't have a library card #. That's not going to help me.

Answer 4

240100447204

Answer 5

try that

Answer 6

lemme know what happens

Answer 7

It worked but I don't see it helping me too much.

Answer 8

ok you shouldve pressed the math section

Answer 9

I did.

Answer 10

ok then you fill out the information on the bottom it shouldve let you type in your qestion

Answer 11

Would this be algebra I or II?

Answer 12

algebra 2

Answer 13

What subtopic?

Answer 14

what are your choices

Answer 15

would it be graphing functions?

Answer 16

yes

Answer 17

I just need to know how to graph them.

Answer 18

girl go the bottom of tha page and get a tutor a live tutor will help you out

Answer 19

I don't like that site.

Answer 20

lol ok then well their helpful i jsut uesd them rite now and they gave me the rite answer to everyting

Answer 21

Brizy, here's something else you can also try. Go to http://fooplot.com. It will graph the equations for you and you can see what quadrants they are in.

You do have to solve for y first. So your first equation in A would be:
3x + 2y = -15
2y = -3x - 15
y = (-3/2)x - (15/2)

Then you'd enter everything right of the "=" sign on that website. Hope that helps.

Answer 22

now thats coool im gonna try that

Answer 23

Yeah that seems complicated :-(

Answer 24

my god girl you are hard to please

Answer 25

Lol I've herd that before :-)

Answer 26

Haha. It does take some work, but that process should at least make it easier.

Answer 27

ya try it

Answer 28

oh shadowfiend was here

Answer 29

Still is.

Answer 30

aaaaahhhhhh

Answer 31

have i metntioned you look wonderful today:)

Answer 32

BrizyBaby—the easiest way to answer these question is usually to graph them, honestly.

Answer 33

I don't know how to graph the equations....that's what I need help with.

Answer 34

Got it! Now we're at the heart of the problem :)

Answer 35

Let's start with A then. We have two equations:

3x + 2y = -15
x - 4y = -20

Answer 36

well i give up nice meeting you thoug Brizzy

Answer 37

I need a easy way to know how to graph them.

Answer 38

You too aminah.love18

Answer 39

I find it easiest to graph equations when they're in y = mx + b (slope-intercept) form. So first things first, we try to solve the equations for y:

\[\begin{align}
3x + 2y &= -15\\
2y &= -3x - 15\\
y &= \frac{-3x - 15}{2} = -\frac{3}{2}x - \frac{15}{2}
\end{align}\]

And the other one:

\[\begin{align}
x - 4y &= -20\\
-4y &= -20 - x\\
y &= \frac{-20 - x}{4} = \frac{-20}{4} - \frac{1}{4}x\\
y &= -5 - \frac{1}{4}x = -\frac{1}{4}x - 5
\end{align}\]

Answer 40

So, we now have:

y = -3/2 x - 15/2
y = -1/4x - 5

The first thing to notice is that both of these have a negative slope. Do you know what a negative slope means on a graph?

Answer 41

I don't get how you did the equations but yeah a negative slope goes down left to right.

Answer 42

Whoops. Sorry then, let's go back to that :)

Let's start with 3x + 2y = -15. We're trying to solve for y. That means we need y alone.

Remember that an equation doesn't change if we subtract the same thing from both sides. So first things first, we move the 3x to the right:

3x + 2y = -15
3x - 3x + 2y = -15 - 3x

Subtract 3x from both sides, 3x - 3x is 0:

0 + 2y = -15 - 3x
2y = -15 - 3x

(We leave off the 0.) Then we need to get rid of the 2. Dividing the same thing from both sides also leaves the equation unchanged, so we'll divide by 2:

y = (-15 - 3x) / 2
y = -15/2 - 3/2 x

Does that make more sense?

Answer 43

yeah. So the points are -7.5 and -1.5?

Answer 44

Close! :)

This means that the line is, like we said, going top left to bottom right. It means for every 3 units down that it goes, it goes two units to the right. And it means that it meets the y axis at -7.5. A quick, semi-accurate drawing: