Question

PLEASE HELP FOR 48 POINTS PLEASE!



show/explain your answer and work

Answer 1

Answer:

c  This is the direct variation

Step-by-step explanation:

The equation for direct variation is y= kx

Solving this for k

y/x =k

So y/x must be a constant

a.  9/3 =3

2/7 does not =3  so this is not a direct variation

b 1/2 = .5

-3/6 = -.5

This is not the same so this is not a direct variation

c.  27/9 =3

18/6 =3

9/3 =3

This is a direct variation with a constant of 3

d 5/-7 = -5/7

1/-3 = -1/3

This is not the same so this is not a direct variation

Answer 2

Answer:

C

Step-by-step explanation:

The equation you are looking for must look something like y = k*x

The easiest way to find it is to try 2 points to see if k would be equal in both cases. Do this for each choice.

A

• y = kx
• x = 5
• y = 1
• y = kx
• 1 = k*5
• k = 1/5

• y = kx
• x = 7
• y = 2
• 2 = k*7
• k = 2/7

k is not the same in both case. A is not the  answer.

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B

Using the steps above

• x = 10
• y = -6
• k = -6/10 = - 0.6

• x = 6
• y = -3
• k = - 3/6
• k = -1/2          

B is not the answer.

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C

• x = 3
• y = 9
• y = kx
• 9 = k*3
• k = 9/3
• k = 3

• x = 6
• y = 18
• y = kx
• 18 = 6k
• 18/6 = 6/6 k
• k = 3

C is the answer

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You can try D yourself