Question

Please can you help? I have a few questions after this as well, if you can. http://gyazo.com/c7ea43f3aad882930876dbb1f73075bc

Answer 1

@e.mccormick Sorry, but do you think maybe you could help me with a few more problems? If it's a bother, never mind.

Answer 2

Need help?

Answer 3

OK, so what we talked about yesterday. Did you find the vertices?

Answer 4

No. I can try to now?

Answer 5

Sure.

Answer 6

Have you tried graphing the constraints?

Answer 7

No, I haven't. I'm still trying to figure it out. It's all a bit confusing still.

Answer 8

What method are you going to use to graph? Calculator, paper, a graphing web site?

Answer 9

The site you used yesterday?

Answer 10

https://www.desmos.com/calculator

Answer 11

OK, carefully put in the calculations. Make sure to get the \(\le\), \(\ge\), fractions, and so on right.

Answer 12

http://gyazo.com/5013c6f7ec2861be5e96ca9d478a68bb

Answer 13

OK. See the area near the center in quad 1 that has all four colors?

Answer 14

Yeah.

Answer 15

What are the corner points in (x,y) coordinates?

Answer 16

Uh..(1.5,1,5?)

Answer 17

That is one of them. (0,0) is another (I took the easy one. =P) what are the others?

Answer 18

Uhm, (2.5, 0.5) (2, 1)

Answer 19

Hmmm.... the others are actually on the x and y axis lines. Take another try at it.

Answer 20

Okay..

Answer 21

(0,1) (3,0)?

Answer 22

/cheer

Yep. Here is my version, with those marked:
https://www.desmos.com/calculator/3n4fnwk2l4

Answer 23

Thank you!

Answer 24

Next, you put each of (0,0), (1.5,1,5), (0,1), and (3,0) into the equation. One at a time. See what answers you get.

Answer 25

C=5x-4y

Looking for Maximizes.

C=5(0)-4(0)
C=0-0
C=0

I don't think that will be the max one....

Try the other three and see.

Answer 26

Okay.

Answer 27

Working on it.

Answer 28

C=5x-4y

C=5(1.5) - 4(1.5)
C=7.5 - 6
C= 1.5


C=5x-4y

C=5(0) - 4(1)
C=4


C=5x-4y

C=5(3) - 4(0)
C=15

Answer 29

Bingo!

Answer 30

So would 15 be the answer?

Answer 31

The 15 one is highest, but your lowest was not 4. It was -4. Oops.

Answer 32

Well, aren't they asking for a POINT in the feasible region?

Answer 33

Oh, okay. And yes.

Answer 34

Still, since the -4 is not needed, no big deal. Just be careful because that sort of mistake is what trips people up!

And yes, the last step is to translate that back to the proper point once you know which has the maximum value.

Answer 35

Good advice...

Answer 36

So it would be 3,0?

Answer 37

It is always good to recheck a question at times to make sure you are answering the right thing. In this case, you found the maximum. Great! That was required, but the form of the answer was not 15. It was (3,0), as Splash pointed out. Very wise to take a second or even third look just to be certain you do not shot yourself in the foot!

Answer 38

Thank you!

Answer 39

np. Have fun!