Question

Please help me! Showing working out as well thanks!

Answer 1

k=8

Answer 2

sorry, that's the wrong answer. I have the answer but I want to know how to get it.

Answer 3

how man

Answer 4

because i was given the answer and i want to know the working out for it. I don't want to say the answer yet because i want to know if someone can solve it correctly or get the right answer without given the answer.

Answer 5

just plug in the x,y at point B
z = 4k+6
obviously z is greatest when k is larger
choose the largest k value

Answer 6

yeh that's wat i thought but that's not the answer which referring to wat u say it's E but it's not.

Answer 7

it's actually D which is k=3 and I do not know why but yeh, it's the answer that is printed on the sheet and I didn't have time to ask my teacher yet.

Answer 8

oh sorry i didn't read question properly, even though we want z to be as large as possible it still has to be at point B
if k=10 , then point A would yield maximum --> z = 5k = 50

Answer 9

huh, i don't get it?

Answer 10

for every k value (answer choice)
compute z = xk +2y for points A,B,C .... if point B yields greatest value then that is the answer

Answer 11

still don't get it because if u substiute point A, B and C into the equation u still have the k there for example- point A(5,0) will be k(5)+2(0)
z=5k+0
how do u know which value is correct?

Answer 12

and wat value is k?

Answer 13

let me try this approach:
point A --> z = 5k
point B --> z = 4k+6
point C --> z = 12

the goal is to find k such that 4k+6 is greatest
4k +6 > 12
4k > 6
k > 3/2

4k+6 > 5k
6 > k

--> 3/2 < k < 6
any k value in this interval will yield point B as giving maximum z value

Answer 14

ok but wouldn't point C be 12k? not 12 where did the k go?

Answer 15

point C is (0,6) correct?
x is 0, 0 times k = 0

Answer 16

oh yeh, my bad.

Answer 17

hmm i do get ur approach to this question but i think i might not remember it for the test i have tomorrow. I am also thinking that there is an easier method to approach this?

Answer 18

yes there is, just plug in the different k values for each point (assuming multiple choice)

Answer 19

k=1:
point A --> z = 5
point B --> z = 10
point C --> z = 12
Wrong
....
continue

Answer 20

wait wait how do u mean by wrong? how do u know it's wrong? and wat are we trying to find?

Answer 21

wat do u mean by wrong*?

Answer 22

point B has to yield maximum z value right?
if it doesn't then its the wrong k value

Answer 23

yep, so wouldn't it just be k=10 why isn't it?

Answer 24

k=10:
point A --> z = 50
point B --> z = 46
point C --> z = 12

see how point A yields greater z value

Answer 25

yeh....