Direct Variation
This is the formula for direct variation
y= kx or y/x=k
This is the formula for inverse variation
What is y = k/x or xy=k
On a map, distance in km and distance in cm varies directly, and 25 km are represented by 2cm. If two cities are 7cm apart on the map, what is the actual distance between them?
What is 87.5 km
The time it takes to fly from Los Angeles to New York varies inversely as the speed of the plane. If the trip takes 6 hours at 900 km/h, how long would it take at 800 km/h?
What is 6.75 hours
6+sqrt(2x+3)=7
x=-1
The electric current I, is amperes, in a circuit varies directly as the voltage V. When 12 volts are applied, the current is 4 amperes. What is the current when 18 volts are applied?
What is 6 amperes
Albertson’s found that the demand for Coke products varies inversely as the price of the product. When the price of a Coke product is $2.75, the weekly demand is 1250. Find the weekly demand if the price is raised to $4.00.
What is 859
The solution(s) of:
sqrt(-9x-14)=0
x=-14/9
Y is directly proportional to X. y = 16 when x =4. Find y when x = 12.
What is 48.
y is inversely proportional to x. If y = 7 when x = 4, find y when x = 28.
What is 1
The time taken to cycle a particular distance varies inversely with the speed of the bicycle. Tim takes 3 hours to reach his destination traveling at a constant speed of 12 miles per hour.
Find the constant of proportionality
36 miles
The volume of paint used, V liters, is directly proportional to the area, A square feet, that the paint can cover. 5 liters of paint can cover a wall with an area of 75 square feet.
Find the constant of proportionality.
1/15
x=5+sqrt(6x-35)
x=6, x=10
y varies directly with x. If y = 15 when x = 18, find y when x = 1.6.
What is 1.3333...
The time taken to cycle a particular distance varies inversely with the speed of the bicycle. Tim takes 3 hours to reach his destination traveling at a constant speed of 12 miles per hour.
How long would it take Tim to reach his destination if he travels at a constant speed of 15 miles per hour?
2.4 Hours
The volume of paint used, V liters, is directly proportional to the area, A square feet, that the paint can cover. 5 liters of paint can cover a wall with an area of 75 square feet.
How much paint would be needed to cover an area of 180 square feet?
12 liters
n-2 = sqrt(2n-1)
n=5
y varies directly as x. if y = 375 when x = 5, find y when x = 3.
What is 225
x varies inversely as y. x is 16 when y is 5. Find x when y is 2.
What is 40
Disregarding wind resistance, the distance a body falls from rest varies directly as the square of the time it falls. If a skydiver falls 64 ft in 2 seconds, how far will he fall in 10 seconds?
What is 1600 ft
In planning a trip, the time it takes to make the trip varies inversely with the rate of the car. If I take Route A and average 40 mph, it will take 9.5 hours to complete the trip. If I go by Route B and average 50 mph, how long will the trip take?
What is 7.6 hours
The solution(s) of: sqrt(5x+6) = x
x=6