Practice C 8-2

Name

Date

Class

Practice C

LESSON

8-2

Multiplying and Dividing Rational Expressions

Multiply. Assume all expressions are defined. 3 6 15x 2y 2 2x y _______ 1. ______ • 4 5x 2y 3 10x y

 40 _______  14 • 8x _______ 2. 2x 2 6x  42 x  25

4

3y ____

8 ________  3 x ⫺ 5

5x x  10x  48 x  12x • 2_____________ __________ 3. 4 3 2 x3 2x  16x 3

2

2 9x  3x x  15x  18 • ______________ 4. 3_____________ 2 3 2 9x  36x  108 36x  12x

2

3

x⫺1 _________ 12  x ⫺ 2 

4 x ⫹ 3  Divide. Assume all expressions are defined. 3 2 xy  2y 4x y  ___________ 5. _____ 6 2 2x y x  3x  10

x ⫺ 5  2________ x3

3 12 6y 7m 3x 3 4x y ________  7. ______ y 5x 2 3m 3y

x 2  6x  24  3_____________ x 3  9x 2  6x 6. 3____________ x x 2  x  20

1 ______________ x ⫺ 5  x ⫺ 1  x 2 9x  18 x 2  12x  72  ___________ 8. 4_____________ 8x 2  32x  40 x 2  2x  15

2y ___ x

2

x⫹3 ________ 2 x ⫺ 1 

2

Solve. Check your solution. 2 x  4x  168  20 9. 4_____________ 2x  12

 3x  18  13 10. x___________ x3 2

x ⫽ 17

x ⫽ 19

 3x  10  7 11. x___________ x2

x  18x  40  5 12. 2_____________ 2x  10

2

2

x⫽9

No solution Solve.

13. The formula for the volume of a cylinder is r 2h and the formula for its surface area is 2r 2  2rh, where r is the radius and h is the height. A cylindrical industrial storage tank has a surface area to-volume ratio of 3. If the height of the cylindrical tank is 2 meters, what is the radius?

1 meter

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5/11/06 5:09:38 PM