MATH 115 TEST #4 (Chapter 7) Spring 04

Math 115 Practice Test #5 (Chapters 8 & 9)

36 25 24 1. Simplify. a) b) -49 c)  d) 2 81 100

2. Simplify. Assume all variables represent positive numbers.

3 5 2 a) 48x 3 y 2 b) 72a4 b 7 c) 53 128x6 y 5 d) 128c d 4

3. Simplify. -2 5 5 1 a) b) c) 20 12 2

4. Perform the indicated operations. a) (4 2+ 1)( 3 - 5) b) 3 18- 2 32 + 5 50 + 72

5. Rationalize the denominators. 5 2 a) b) 7a 3- 5

6. Solve each equation. a) 6x  2  3x  5 b) 8x- 2 = x

7. Solve each equation by the method indicated. a) by factoring 2x2 - 5 x - 7 = 0

b) by using the square root property x2 = 45

c) by completing the Square x2 -8 x - 7 = 0

d) by using the Quadratic Formula 5x2 = - 8 x - 1

8. Solve each quadratic equation by your method of choice. a) 6x 2 18x  0 b) 9x 2 12x  4

c) 4x 2 16 d) (x + 3)2 = 49

9. In the right triangle ABC, a = 2 cm, b = 6 cm, find the side c by using the Pythagorean

Theorem. B c a

C A b ______

Solutions:

5 6 1. a) 3 2 b) Not a real number c) - d) 9 5

2. a) 4xy 3 x b) 6a2 b 3 2 b c) 20x2 y3 2 y 2 d) 6c2 d 2 c

15 2 3. a) -1 b) c) 6 2 4. a) 4 6- 20 2 + 3 - 5 b) 32 2

35a 5. a) b) -3 - 5 7a 6. a) x=3; x = 1 needs to be rejected since it is extraneous! b) x = 2

7 -4 11 7. a) x=; x = - 1 b) x = 3 5 c) x = 4 23 d) x = 2 5 2 8. a) x= -3; x = 0 b) x = - c) x = 2 d) x=4, x = - 10 3 9. 2 10 cm