Question

Did I get this correct?

http://prntscr.com/rqmv2

Answer 1

I'm confident that if you knew what you were doing, you wouldn't have to ask.

Answer 2

This is my final. I'm just making sure. I solved the first equation and got:
y > - x - 5

The second one:
y > -3x + 3, I know it's greater than therefor above the origin. The green shaded area looked good too me. Just wanted to know if I was right.

Answer 3

If not, I'll resolve it.

Answer 4

You don't even really need to do all of that. Just take a point in the solution region and test it.

Answer 5

So, pick a point in one of the quadrants, and see if it works in the way you expect.

Answer 6

What do you mean?

Answer 7

Take (2,0), for example. Does it satisfy the inequalities?

Answer 8

y > -2x + 0 <-- ?

Answer 9

Test (x,y) = (2,-2)

c'mon @Sephl, doing that is not difficult at all. Plug the point into the inequalities and see which one works

Answer 10

Can you demonstrate for me? I've been putting them in y=mx+b and looking at it graphically.

Answer 11

You don't know how to test points? This is what frustrates me with students. So many don't know how to do basic things.

Answer 12

x=2, y = 0

x-y < 5 2 -0 < 5 check
3x+y > 3 3*2 + 0 > 3 check

Answer 13

y>1+x
Test the point (x,y)=(1,2)
2>1+1
2>2
The inequality does not work with that point. That means that whole side of the line, is not part of it.
Now do what I did for your question but choose a point that is not part of the point.

Answer 14

You guys are just confusing me more.

Answer 15

part of the line*

Answer 16

(2,0) is in the green area, and it satisfies the inequalities you chose. that makes it a correct answer.

Answer 17

Okay, wait, I see.

Answer 18

testing 0,0 is easiest

Answer 19

Do I need to put the equation in y=mx+b first?

Answer 20

That's only if it isn't part of the line.

Answer 21

(0,0) isn't in the solution region

Answer 22

If it failed one of the inequalities, you would know that your choice was wrong.

Answer 23

Do I need to put it in y=mx+b

Answer 24

No.

Answer 25

Here's what you need to do:

`1.` Take the inequality you believe is correct
`2.` Test a point in the solution region by plugging it into both inequalities
`3.` If both inequalities are true, then the inequality you chose is correct.

`1.` x - y < 5 and 3x + y > 3
`2.` (2,0) a test point in the solution region:

2 - 0 < 5 and 3(2) - 0 > 3
2 < 5 and 6 > 3

`3.`
2 < 5 True
6 > 3 True

So the inequality you guessed worked, therefore, it is correct.

Answer 26

Look, if you have made a correct set of choices of inequalities to describe the green region, *ANY* point in the green region of your choosing will satisfy those inequalities. Any point outside the green region will not. Conversely, if you find a point in the green region which does not satisfy one or more of the inequalities, you've chosen the wrong inequalities to describe the green region.

Answer 27

I'd modify the first #3 to "If and only if" but otherwise nicely written.