7th Grade Math

Test PracticeT

184 Rational Numbers

C 48. OPEN ENDED Write a convincing argument that 3^0 = 1 using the fact that

34 = 81, 3^3 = 27, 3^2 = 9, and 3^1 = 3.

49. REASONING Order 8-^8 , 8^3 , and 8^0 from greatest to least. Explain your
    reasoning.


50. CHALLENGE Compare and contrast x-n and xn. Then give a numerical
    example to show the relationship.


51. E WRITE MATH Explain the meaning of a negative exponent when the
    base is 10.

ALGEBRA Simplify each expression. (Lesson 4A)

56. 36 · 3 57. x^2 · x^4 58. 5

5

_

52

59. (n^4 )(- 2 n^3 )


60. SPORTS The length of an athletic field is twice its width. Write an expression
    in simplest form that represents the area of the field. (Lesson 4A)


61. WHALES During the first year, a baby whale gains about 27 _^3
    5
    tons. What is
    the average weight gain in simplest form per month? (Lesson 3D)


62. PETS Hannah made the dog bed shown. If the area of the dog

x ft^1 ft

1

3

bed is 2 _^23 square feet, what is the length of the bed? (Lesson 3D)

52. Which is 15-^5 written as a fraction?
    A. _^1
    55

C. _^1

15

B. _^1

155

D. - _^1

155

53. The table shows the length of a cell
    and virus.

(^) Structure Length (m)
Cell 10 -^4
Virus 1 0 -^7
Which of the following represents the
length of a virus using a positive
exponent?
F. 10 7 H. ^1
107
G. 7 10 I. - ^1
10 7

54. SHORT RESPONSE Rewrite the
    numbers with negative exponents so they
    have positive exponents.

Negative

Exponents m

• (^5) b- (^3) · b- 1 x_-^5
  x-^3
  Positive
  Exponents^

55. The prefix centi equals 0.01. Which of the
    following represents the decimal written
    with a negative exponent?
    A. 10
    
    
    • 1
    
    
    
    

B. 10

• 2

C. 10 1

D. 10 2

176_189_C3L4_895130.indd 184 12/31/09 12:50 PM