Inverse
Joint
Combined
Quadratic
State the relationship
100

Y varies inversely as X. Write the inverse-variation equation. Y=36 when X=9

Y= 324/X

100

Y varies Jointly as X and Z Write the Joint-Variation equation. Y=-108 when X=-4 and Z=3

Y=9XZ

100

Z varies jointly as X and Y, and inversely as W. write the combined-variation equation. Z=3 when X=4, y=-2 and W=-4

Z=2XY/W

100

y varies directly as the square of x. Write the quadratic variation equation. Y=180 and x=6

y=5x2

100
Y=K/X
Inverse Variation
200

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

Y=4/X

200

Y varies Jointly as X and Z Write the Joint-Variation equation. Y=15 when X=9 and Z=1.5

Y=10/9XZ

200

Z varies jointly as X and Y, and inversely as W. write the combined-variation equation. Z=36 when X=9, Y=10 and W=15

Z=6XY/W

200

Y varies inversely with the square of x. Write the quadratic variation equation. y=14 and x=5

y=350/x2

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

Y varies inversely as X. Write the inverse-variation equation, and find Y for the given value of X. Y=14 when X=8; X-value: 10

Y=112/X; 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; 283.5

300

Z varies jointly as X and Y, and inversely as W. write the combined-variation equation, and find X 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=2XY/7W; 8/9

300

P varies directly with the square of I. Find the quadratic variation equation. p=320 and x=4

p=20I2

300
Y=KXZ
Joint Variation
400

Y varies inversely as X. Write the inverse-variation equation, and find Y for the given value of X. Y=1000 when X=0.2; X-values: 10^2

Y=200/X; 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=101; X=105 and Z=102

Y=10XZ; 108

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

Daily Double!



What letter symbolizes the constant of variation?

K

400
y=-108 when X=-4 and Z=3
Joint variation
500

Y varies inversely as X. Write the inverse-variation equation, and find Y for the given values of X. Y=13.5 when X= 4.5 X-values: 0.5,1

Y=60.75/X; 121.5,60.75

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; 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

The intensity (I) of a radio signal varies inversely as the square of its distance (d) from the transmitter. If I = 5 microvolts when d = 10 kilometers, find I when d = 5 kilometers

I = 20 microvolts

500
The number of minutes needed to solve an exercise set of variation problems varies directly as the number of problems and inversely as the number of people working on the solutions. It takes 4 people 36 minutes to solve 18 problems. How many minutes will it take 6 people to solve 42 problems?
Combined variation
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