Direct Proportions
Which one is an example of a direct proportion: y = 5x OR -3x + 2y =0 First, Second, Both, or Neither
Both
If y varies inversely with x, write an equation connecting x and y when x=9, the value of y=4
y=36/x
Find the constant of proportionality for this inverse proportion: x: 2, 7, 10 y: 35, 10, 7
K=70
Write a direct proportion equation that describes a van (v) that gets 20 miles per gallon of gas (g).
V= 20g
Y= 2x
When x: 1, 2, 3
y: 2, 4, 6
Find the missing variable of Direct Proportion (2,y) and (10,15)
y= 3
The cost of a $300 wedding gift is being split between multiple people. Create a table when x: 3, 4, 5
y: 100, 75, 60
Find the constant of proportionality for this inverse proportion: x: 1.2, 1.5, 2.4 y: 5, 4, 2.5
K=6
The cost of tomatoes varies directly with the price per pound. A pound of tomatoes costs $0.78.
Write a direct proportion equation and then find how much it would cost to buy 5 tomatoes.
y= 0.78x
$3.90 to buy 5 tomatoes
y= 3x - 2 When x: 1, 2, 3
y: 1, 4, 7
Find the missing variable of Direct Proportion (2/3, 2) and (x,6)
x=2
Find the missing variable in this inverse proportion (4,25) and (5, p)
p=20
Find the constant of proportionality for this direct proportion: x: 2, 6, 10 y: 4.2, 12.6, 21
k=2.1
The number of hours it takes to mow nine lawns is inversely proportional to the number of gardeners. It take 3 gardeners 4 hours to mow nine lawns. Find how many hours it would take 1 gardener to mow the same nine lawns.
It would take one gardener 12 hours to mow nine lawns.
y= x2 + 1 When x: -2, -1, 0, 1, 2
y: 5, 2, 1, 2, 5
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 a direct proportion
Find the missing variable in this inverse proportion (12,y) and (18, 6)
y= 9
Find the constant of proportionality for this direct proportion: x: 2, 8, 16 y: 9, 36, 72
k=4.5
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
y= .5x When x: 1, 2, 3
y: 1/2, 1, 1 1/2
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.
Find the missing variable in this inverse proportion. (9, f) and (12, 6)
f= 8
What is the constant of proportionality for this set of values? x: 0, 2, 4, 6 y: 3, 5, 7, 9
There is no constant, this is not direct or inverse variation.
The time, T hours, to travel a fixed distance varies inversely with the rate, R, of travel. If T=4 and R=20 miles per hour, find T when R=50 miles per hour.
T= 1.6
y= -|x| - 1 When x: -2, -1, 0, 1
y: -3, -2, -1, -2