Direct Variation
Inverse Variation
Solve for the Constant
Word Problems
Shifts
100
Which one is an example of direct Variation: y = 5x OR -3x + 2y =0 First, Second, Both, or Neither
Both
100
If y varies inversely with x, write and equation when x=9 and y=4
y=36/x
100
Find the Constant of Variation for: 


x: 2, 7, 10 

y: 35, 10, 7

K=70
100

If w varies inversely as b and w = -6 when b = 14, find w when b = -11.

w=7.6
100
Write the equation for an inverse variation function that has been shifted two units to the right.
y=1/(x-2)
200

If x and y vary directly and x=10 when y=15, find y when x=2.

y= 3
200
The cost of a $100 wedding gift is being split between multiple people. Write an equation and create a table of values for when x: 3, 4, 5
y: 33.33, 25, 20
200
Find the Constant of Variation for: 


 x: 1.2, 1.5, 2.4 

y: 5, 4, 2.5

K=6
200

As long as the temperatures remains constant, the volume of any gas varies inversely with its pressure. If a helium-filled balloon has a volume of 3.4 cubic decimeters at a pressure of 120 kilopascals, what is its volume at 101.3 kilopascals? Round to two decimal places. 

4.02 cubic decimeters
200
Write the equation for an inverse variation function that has been shifted four units down.
y=1/x -4
300

If x and y vary directly and x=2/3 when y=2, find x when y=6.

x=2
300

If x and y vary inversely and x=4 when y=28, find y when x=3.

y=37.33
300
Find the Constant of Variation: 


 x: 2, 6, 10 

y: 4.2, 12.6, 21

k=2.1
300

The speed of an object falling from rest is directly proportional to the time it has fallen. After an object has fallen for 2.5 seconds, its speed is 24.5m/s. What is its speed after it has fallen for 4 seconds? Round to one decimal place.

39.2m/s
300
Write an equation for an inverse variation function that has a vertical stretch of 6, and has been shifted to the left 4 units.
y=6/(x+4)
400
Does the data in this table represent that y varies directly with x? if so, write an equation.

 x: 4, 5, 11

 y: 3, 4.5, 13.5

Is not Direct Variation.
400

If x and y vary inversely and x=2/3 when y=18, find y when x=3/4.

y=16
400
Find the Constant of Variation: 


 x: 2, 8, 16 

y: 9, 36, 72

k=4.5
400
Your score on a quiz varies directly with how many questions you answer correctly. If you got a 90 on your quiz and you got 30 questions right, write an equation for this relationship.
y = 3x
400
Write an equation for an inverse variation function that has been reflected over the x-axis, and shifted up five units.
y=-1/x  +5
500
The amount of simple interest earned in a savings account varies directly with the amount of money in the savings account. You have $1000 in your savings account and earn $30 in simple interest. How much interest would you earn if you had $1200 in your savings account.
You would earn $36 in simple interest.
500

If x and y vary inversely and x=12.4 when y=6.6, find x when y=8.8.

x= 9.3
500
Find the Constant of Variation: 


 x: 0, 2, 4, 6 

y: 3, 5, 7, 9

There is no constant, this is not direct or inverse variation.
500
The time, T, to travel a fixed distance varies inversely with the rate, R, of travel. If T=4 hr. and R=20 mi/hr. , find T when R=50 mi/hr.
T= 1.6 hr.
500
Write an equation for an inverse variation function that has a vertical stretch of 2, has been reflected over the x-axis, shifted left 3 units and shifted down 7 units.
y=-2/(x+3)  -7
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