Inverse
Joint
Combined
Direct
State the relationship
100

Y varies inversely as X. Write the inverse-variation equation, when Y=36 and X=9. Find Y for the given when x=3.

Y= 324/X;

Y=108

100

Y varies Jointly as X and Z. Write the Joint-Variation equation, and find Y for the given values of X and Z. Y=-108 when X=-4 and Z=3; X=6 and Z=-2

Y=9XZ

Y= -108

100

Z varies jointly as X and Y, and inversely as W. write the combined-variation equation, and find Z for the given values of X,Y, and W. Z=3 when X=3, y=-2 and W=-4; X=6,Y=7,W=-4

Z=2XY/W; 

Z=-21

100

If y varies directly with x and y=2 when x=6. find y when x=9

3

100
Y=K/X
Inverse Variation
200

Y varies inversely as X. Write the inverse-variation equation, when Y=0.5 and X=8. Find Y when X = 5. 

Y=4/X

Y= 0.8

200

Y varies Jointly as X and Z Write the Joint-Variation equation, and find Y for the given values of X and Z. Y=15 when X=9 and Z=1.5; X=18 and Z=3

Y=10/9XZ

Y=60

200

Z varies jointly as X and Y, and inversely as W. write the combined-variation equation, and find Z for the given values of X,Y, and W. Z=36 when X=9, Y=10 and W=15; X=10,Y=18,W=5

Z=6XY/W

Z=216

200

If y varies directly with x and y=80 when x=16. Find y when x=3.

15
200
Y=(K/X)ZY
Combined variation
300

Y varies inversely as X. Write the inverse-variation equation, when Y=14 and X=8. Find Y when x = 10. 

Y=112/X

Y = 11.2

300

Y varies Jointly as X and Z Write the Joint-Variation equation, and find Y for the given values of X and Z. Y=120 when X=8 and Z=20; X=54 and Z=7

Y=3/4XZ

Y=283.5

300

Z varies jointly as X and Y, and inversely as W. write the combined-variation equation, and find Z for the given values of X,Y, and W. Z=100 when X=100, Y=7 and W=2; X=3.5,Y=24,W=27

Z=2/7XY/W

Z=8/9

300

Given that y varies directly with x, use the specified values to write a direct variation equation that relates x and y. x=9 y=27

What is y=3x

300
Y=KXZ
Joint Variation
400

Y varies inversely as X. Write the inverse-variation equation, when Y=1000 and X=0.2. Find Y when x=102

Y=200/X; 

Y=2

400

Y varies Jointly as X and Z. Write the Joint-Variation equation, and find Y for the given values of X and Z. Y=104 when X=102 and Z=10; X=10and Z=102

Y=0.1XZ

Y=1 000 000

400
DAILY DOUBLE!!! A bicycle's pedal gear has 53 teeth and is rotating at 65 revolutions per minute. A chain links the pedal gear to a rear-wheel gear that has 18 teeth and is attached to a 26-inch wheel. At what speed, in miles per hour, is the bicycle traveling?
14.5 miles per hour
400

Given y varies directly with x and y=7 when x=14. Find x when y=9.

18
400

Is y=x/18 an example of direct variation, inverse variation, or neither?

Neither

500

Y varies inversely as X. Write the inverse-variation equation, when Y=13.5 and X= 4.5. Find Y when x = 0.5.

Y=60.75/X

Y=121.5

500

A prism has a height of eight inches, a length of X and a Width of Z. Write an equation for the volume of the prism, and find the volume of the prison when the length is 4 inches and the width is 2 inches

V=8XZ

Y=64 cubic inches

500

The electrical resistance of a wire varies directly as its length and inversely as the square of its diameter. A wire with a length of 200 inches and a diameter of one-quarter of an inch has a resistance of 20 ohms. Find the electrical resistance in a 500 inch wire with the same diameter.

50 Ohms

500

Given that y varies directly with x, use the specified values to write a direct variation equation that relates x and y. Then find x when y = 45 y = 18 x =2

y=22.5

x = 0.8

500

If x and y vary inversely find the missing value. (10 , 12) (x , 5)

x=24
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