Variations

What is the standard equation of direct variation?

• y = kx

• y = k/x

• y = kxz

• y = kx/z

y is directly proportional to x, and y = 24 when x = 4.

What is the value of y when x = 3?

• 18

• 20

• 23

• 43

P is directly proportional to T.

Which of the following could be the graph connecting T and P?

• 
• 
• 
• 

y is inversely proportional to x, and y = 8 when x = 3

What is the equation?

• y = 24x

• y = 24/x

• y = 24

• x = 24

The time (t days) required to build a house is inversely proportional to the number of builders (n), all working at the same rate.

If there are 6 builders, it takes 80 days to complete the house.

How many builders must be employed to build the house in just 16 days?

• 1.2

• 25

• 30

• 36

The electrical voltage V varies jointly as the current I and the resistance R.

What is its translation?

• V=klR

• V=kR

• V=k/IR

• V=kI/R

z varies jointly as x and y and z = 60 when x = 5 and y = 6.

Find z when x = 7 and y = 6

• 84

• 60

• 24

• 30

w varies directly as x and y and inversely as v² and w = 1200 when x = 4, y = 9 and v = 6. Find w when x = 3, y = 12, and v = 10.

• 432

• 4320

• 346

• 243

If y varies inversely as x and y = 3 when x = 4. What is its equation?

• y = 12x

• y = 12/x

• y = x/12

• y = 12

q varies jointly as r and s. If q = 2.4, when r = 0.6 and s = 0.8

Find its equation.

• q=5rs

• q =5/rs

• q=5r/s

• q=5r