Direct Variation
Inverse Variation
Solve for the Constant
Word Problems
More Proportions
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. x=9 and y=4
y=36/x
100
Find the Constant: x: 2, 7, 10 y: 35, 10, 7
K=70
100
Write a function rule that describes a van getting 20mi/gal.
V(g)= 20g
100

y varies directly to the square of x. y = 75 when x=5. Find y when x = 2. 

y=12

200
Find the missing variable of Direct Variation (2,y) and (10,15)
y= 3
200
The cost of a $100 wedding gift is being split between multiple people. Create a table when x: 3, 4, 5
y: 33.33, 25, 20
200
Find the Constant: x: 1.2, 1.5, 2.4 y: 5, 4, 2.5
K=6
200
Write a function rule to calculate the cost of buying tomatoes at $.78 per pound. Then tell me how much it would cost to buy 5 tomatoes.
f(x)= .78x $3.90 to buy 5 tomatoes
200

m is directly proportional to the cube root of n. m=4 when n=8. Find the value of m when n=64.

m=8

300
Find the missing variable of Direct Variation (2/3, 2) and (x,6)
x=2
300
Find the missing variable in this inverse variation (4,28) and (3, p)
p=37.33
300
Find the Constant: x: 2, 6, 10 y: 4.2, 12.6, 21
k=2.1
300
You invest $215 to buy hats for your band and then sell them for $9.50 each. Write a function rule and then tell me how many hats do you need to sell in order to get back your investment.
f(x)= 9.50x - 215 Must sell 23 Hats
300

w varies directly to the square of v. w=80 when v=4. Find v when w=45

v=3 or v=-3

400
Does the data in this table represent that y varies directly with x? if it does write an equation. x: 4, 5, 11 y: 3, 4.5, 13.5
Is not Direct Variation.
400
Find the missing variable in this inverse variation (3/4,y) and (2/3,18)
y=16
400
Find the Constant: 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

y varies inversely to x2. y=-4 when x=3. Find x when y=-12. Express your answer correct to 3 decimal places.

x=1.732

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
Find the missing variable in this inverse variation. (12.4,6.6) and (f,8.8)
f= 9.3
500
Find the Constant: 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 inverselt 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

y varies inversely to x3. y=7 when x=2. Find x when y=8. Express your answer to 3 significant figures.

x=1.91

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