Question

Which does not show a direct variation between x and y?

y = 4/x
y = 0.5x
y = 7x
y= x/9

Answer 1

I think its y= x/9

Answer 2

How did you get that?

Answer 3

Its just common sense if you look at the rest of the answers
4/x
0.5x
7x
And then its x/9

Answer 4

x/9 is the only one that is different from the other ones

Answer 5

.........That doent really help for more problems i may have to slove later. Thanks any way.

Answer 6

@Nnesha or @Directrix could you please show me how to get this?

Answer 7

again direct variation u use this equation for it
y = kx

Answer 8

So do I plug in this time?

Answer 9

nope which equation are there in the form of y = kx
if you solve this equation for k
what you should get ?

Answer 10

direct variation means
y = k x
where k is some number.
remember that x/9 can be written as
1/9 * x

which means k= 1/9 so you have direct variation

Words of @phi

Answer 11

I see

Answer 12

Question from @phi

all the direct variations will be number times x

which choice is not "number times x" ?

Answer 13

X/9

Answer 14

I think

Answer 15

@Legends I think i see where you were going with this.....i just did not understand. Thanks.

Answer 16

@Bananas1234 awesome. Nice work

Answer 17

Why did you choose y = x/9. It is the same as y = (1/9) * x which is a number times x as phi said. @Bananas1234

Answer 18

y= x/9 shows direct variation. It is not the answer to this question.

Answer 19

Y = 0.5x?

Answer 20

phi says that is a number times x so it is direct variation.

Answer 21

remember this equation for direct variation
\(\huge\color{green}{{\rm y = k}\rm x}\)

Answer 22

ummm im still confused...sorry :(

Answer 23

@Bananas1234

Which option has x in the denominator?

Answer 24

the first one

Answer 25

y = 4/x = 4 * (1/x)

Is that a number (4) times just an X ?

In other words, is x the same as 1/x ?

Answer 26

Is 9 the same as 1/9 ?

Answer 27

no

Answer 28

Okay.

Answer 29

y = 4/x = 4 * (1/x)

Is that a number (4) times just an X ?

Answer 30

No. 4 * (1/x) is not a number times plain x.

So, there is your answer.

Answer 31

I think i get it, it will just take some more practice ;). Thank you again.

Answer 32

You are welcome.