Question

for what value of k are the graphs of y=3x+4 and 2y=kx+9 parallel?
REWARDING MEDAL

Answer 1

y=3x+4
y=kx/2 + 4.5

Answer 2

y=3x+4 and 2y=kx+9
don't worry about the y-intercepts, focus on slopes

y=3x
2y=kx ---> y= (1/2)k x
so
3=(1/2)k
k=1.5

Answer 3

Sry i misread the question
Parallel graphs have the same slope
Make sure that the slope of kx/2 is equal to 3

Answer 4

Meaning that shouldn't the answer be 6?
6x/2 = 3x

Answer 5

y=3x+4 and
2y=kx+9

dlopes are
3x and kx91/2)
they have to be equal
3x=(1/2)kx
3=(1/2)k
k=1.5

Answer 6

The slopes y=3x+4 and y=6x/2 + 4.5 are parallel
Meaning that k is equal to 6

Answer 7

i am really confused @SolomonZelman has a different answer than what @KirbyLegs has what should the answer be and how is it done

Answer 8

Soloman is correct except that he forgot to put the equation into y=mx+b form. That messed up his problem.

If you graph the two graphs you will see that my two equations are parallel because of their equal slope.

Answer 9

so can you do it again but this time step by step with me please @KirbyLegs

Answer 10

You have one graph, which is y=3x+4
You then have to put the second graph into y=mx+b form
2y=kx+9
Divide the two to each side, giving you
y=kx/2 + 4.5

Are you with me so far?

Answer 11

yeah i understand

Answer 12

keep going

Answer 13

@KirbyLegs

Answer 14

Sorry I got to go. Just very quickly though
Parallel graphs have the same exact slope
In the one graph you have the slope is = to 3
Make kx/2 = 3

Multiply 2 to both sides

kx = 3

k=3

Answer 15

oh okay i get it thanks @KirbyLegs

Answer 16

@SolomonZelman what do you think...i see that he did a pretty good job

Answer 17

I divided instead of multiplying, my bad.

Answer 18

so hes right

Answer 19

Both lines should have same slope to be parallel. In an equation x=mx+b, the slope is m, so for y=3x+4, the slope is 3, and for 2y=kx+9, the slope is k/2, so for them to have the same slope, k/2 =3, so k = 6. !

Answer 20

yes he is, it's 6.