Variations Alg.2

Suppose y varies jointly as x & z. 
If y = -180 when z = 15
and x = -3,
then find y when x = 7 and z = -5.

• -140
• 140
• -4
• 4

Is this a direct variation?
y=2x

• yes
• no

The volume V of a gas kept at a constant temperature varies inversely as the pressure p.
If the pressure is 24 pounds per square inch, the volume is 15 cubic feet.
What will be the volume when the pressure is 30 pounds per square inch?

• 8 cubic feet
• 10 cubic feet
• 12 cubic feet
• 14 cubic feet

If f varies jointly as q² and h, and f = 96 when q = 4 and h = 3, find q when f = 48 and h = 6.

• 4

• 2

• 6

• 3

What is the constant (k) in this inverse variation?
y = 400/x

• x
• y
• 400
• Not enough information given

What type of variation does this scenario represent?
The length of time you charge your cell phone
and the battery power 

• direct variation
• inverse variation
• joint variation
• none of these

Suppose p varies directly as r, and p varies inversely as t.
t = 20 when p = 4 and r = 2.
Find t when r = 10 and p = -5.

• 80
• -80
• 4
• -20

Suppose p varies directly as r, and p varies inversely as t.
t = 20 when p = 4 and r = 2.
Find t when r = 10 and p = -5.

• 80
• -80
• 4
• -20

H varies directly as the square root of F and inversely as the square of G. Given that the constant is k, find the relation betweehn H, F and G.

• $H=\frac{kF^2}{G^2}$

• $H=\frac{kG^2}{\sqrt{F}}$

• $H=\frac{k\sqrt{F}}{G^2}$

• $H=\frac{k\sqrt{F}}{G}$

What type of variation does this scenario represent?
The grade you earn in a class
and the number of assignments you complete
and the number of hours you study

• direct variation
• inverse variation
• joint variation
• none of these