Directly and Inversely Proportional Equations

Determine if the relationship between the two quantities is a direct variation. Explain your reasoning.

• yes, the constant of variation is 1/2

• yes, the constant of variation is 2

• no, there is constant of variation.

Determine if the relationship between the two quantities is a direct variation. Explain your reasoning.

• yes, the constant of variation is 8.

• no, there is no constant of variation

• yes, the constant of variation is 1/8

Determine if there is a constant of variation. If so, explain what it represents.

The equation y = 24 x represents the number of bottles of water y in x packages.

• The constant of variation is 24. This means that there are 24 bottles of water in each package.

• There is no constant of variation. The number of bottles varies per package.

If y varies inversely as x and x=5 when y=20, then what is the constant of variation, k?

• 121

• 4

• 100

• 6

Is the given table a direct variation? If so, what is the constant of variation?

• Yes; 1/3

• Yes; 3

• Yes; 5

• No

Suppose y varies jointly as x & z. 
If y = -180 when z = 15
and x = -3,
then find y when x = 7 and z = -5.

• -140

• 140

• -4

• 4

Is the given table a direct or inverse variation? What is the constant of variation?

• Direct, 12

• Inverse, 12

• Direct, 1/12

• Inverse, 1/12

If y is directly proportional to x and y=6 when x=2, find the value of y when x=11.

If y is inversely proportional to x and y=4 when x=3, find the value of y when x=6.

Jeremy uses 400 g of flour to make 8 muffins. How much flour would he need to make 30 muffins? Is it direct or inverse proportion problem?

• Direct proportion

• Indirect proportion