Direct Proportionality

What is the value of k in the following equation? y = 2/7 x

• 4

• -4

• 2/7

• 7

For an equation to be directly proportional, it must .......

• pass thru two points

• pass thru the origin

• be positive

• not have a fraction

Which equation is not an example of direct proportion?

• y = x

• y = 3x

• y = - 6x

• y = 2/3 x + 5

What means the same thing as direction proportion

• x = y

• direct variation

• y = k + x

• scale up proportion

Y varies directly as x. If y = 39 when x = 52, what is the best answer for k?

• k = 52

• k = 4/3

• k = 3/4

• k = 39/52

If x = 9 when y = 30, and x = 27 when y = 90, does y vary directly with x? If so, what is k equal to

• Yes, k = 10/3

• no

• Yes, k = 3/1

• Yes, k = 9

What is the direct proportion equation for the following information. x = 12, y = 16

• 16 = k(12)

• y = kx

• y = 4/3 x

• k = 16/12

Which of the following table shows a direct proportion relationship?

• 
• 
• 
• 

Which of the following function represents a direct proportion?

• y=1/x

• y=2k/x

• y=kx

• y=0x

Is this a direct proportion?

y=2x

• Yes

• No