WS 7.2 : Find exact answers and rationalize denominators
NAME___________________________
1.
2.
An object moves at a speed of (3+ 2) feet / sec .
How long will it take for the object to travel 10ft?
Pr 2
related by the equation: P =
50
3. Solve the vol. of a sphere formula for the radius
with a volume of 3 units3
V sphere =
(
3
4P
4 3
Pr
3
) ( 3v)
3
(x) that has a vol. of
If
7. The Volume (V) of a cube is related to its surface
æ Sö
è6ø
area (S) with the formula: V= ç ÷
5 3
u
12
V pyramid =
1 2
xh
3
6. A rectangular prism has dimensions 3 x 4 x 7 .
What is the length of the segment that connects
the front left bottom corner to the back upper
corner?
2
vol. is increased by factor of 8, how does S change
3
2
Solve for r.
4. Solve the volume of a pyramid formula for side length
5. The surface area (S) and volume (V) of a sphere
are related by the formula: S=
The power P, in watts, that a circular cell
produces and the radius of the solar cell are
8. Find the radius of a cone that has a volume of
9 cubic inches and a height equal to its radius.
Solve for S
Vol cone =
1
Pr 2 h
3
Hint: Undo power by raising both sides to reciprocal (2/3)!
Simplify each expression. Rationalize all denominators. Assume that all variables are positive.
9.
3
4  3 80
10. 5 2 xy 6  2 2 x 3 y

11. 3 5  21

12.
3
2x  3 4  3 2x 2
13.
5x 4
2x 2 y 3
Simplify each radical expression. Assume that all variables are positive.
14.  81c 48 d 64
15.
5
32 y 25
16.
7
x14 y 35
Divide. Tell whether the divisor is a factor of the dividend.


17. x 3  27  x  3
2x
18.
4

 3x 3  4 x  10  x  2
Simplify. Rationalize all denominators. Assume that all variables are positive.
20. 3 3 16  4 3 54  3 128
75  4 18  2 32
19.


23. 2 y  3 2 4 y  5 2

24.
4 6
2 3


21. 2 5  3 2 5 5  7 2
25.
3 3 2
3
2



22. 2  98 3  18
