Direct and Inverse Variation

y varies directly as x. If y=20 when x=4, find the constant of proportionality. 

• k=4
• k=1/4
• k=1/5
• k=5

What kind of equation is this?
xy=8

• Linear Equation
• Direct Variation
• Inverse Variation
• Joint Variation

Tags

CCSS.HSA.REI.D.10

If y = 15 when x = 12 find y when x = 32.

• 40
• -40
• 5
• -5

Tags

CCSS.6.EE.C.9

 Y varies inversely with x, and y is 0.5 when x is 4. Which equation represents this situation?

• y=2x
• y=2/x
• y=4x
• y=x/2

Tags

TEKS.MATH.2A.6L

TEKS.MATH.A.2D

Suppose y varies directly as x.
If  y = 22.5 when x = 15, find y when x = 20.

• 1.5
• 337.5
• 30
• 16.875

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CCSS.HSA.SSE.A.1

CCSS.HSA.REI.B.3

CCSS.HSF.BF.A.1

CCSS.HSA.CED.A.2

CCSS.HSF.LE.A.2

CCSS.HSA.REI.A.1

Suppose y varies inversely with x.
If y = 150 when x = 2, find y when x = 25.

• 300
• 75
• 1,875
• 12

Tags

CCSS.7.EE.B.4

CCSS.7.EE.B.3

CCSS.7.NS.A.2

The amount of people at your Thanksgiving meal and the amount of leftovers.

• Direct Variation
• Inverse Variation

Tags

TEKS.MATH.2A.6L

TEKS.MATH.A.2D

TEKS.MATH.8.5E

A bottle of 150 vitamins costs $5.25.
If the cost varies directly with the number of vitamins in the bottle,
what should a bottle with 250 vitamins cost?

• $3.15
• $9.65
• $7.75
• $8.75

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.REI.B.3

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.2

CCSS.HSF.LE.A.1

CCSS.HSN.Q.A.1

The time to complete a project varies inversely with the number of employees.
If 3 people can complete the project in 7 days, how long will it take 5 people?

• 12 days
• 4.2 days
• 6.2 days
• 10 days

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.REI.B.3

CCSS.HSA.REI.A.1

The time it takes to fly from Los Angeles to New York varies inversely as the speed of the plane. If the trip takes 6 hours at 900 km/h, how long would it take at 800 km/h?

• 5.33 hours 
• 6.75 hours 
• 12 hours 
• 10 hours 

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSA.CED.A.4