Algebra 1 Common Core Student Edition, Grade 8-9

53. Inflat io n The formula C = c(l + r)n can be used to estimate the future cost C of an
    item due to inflation. Here c represents the current cost of the item, r is the rate of
    inflation, and n is the number of years for the projection. Suppose a video game
    system costs $299 now. How much will the price increase in nine months with an
    annual inflation rate of 3.2%?
    Ch al l en g e 54. Cel l s The number of cells in a cell culture grows exponentially. The number of
    cells in the culture as a function of time is given by the expression where t is
    measured in hours and N is the initial size of the culture.
    a. After 2 hours, there were 144 cells in the culture. What was N1
    b. How many cells were in the culture after 20 minutes?
    c. How many cells were in the culture after 2.5 hours?

Sh o r t

, R e s p o n s e

St a n d a r d i ze d Test Pr ep

55. Which of the following expressions is equivalent to ( 8 x)s?
    CD 16^? CD V&x* Vltoi? CD>8^3
    


56. Which of the following expressions is equivalent to 4 \/b3?
    CD 2bi CD (2b)!
    CD (4b) i CD 4bi


57. Write the expression \/9s 3 + V l 6 s 3 with rational exponents.

Mixed Review

Simplify the following expressions.

58. 5(f2) 3 59. (—2x4) 5


59. -U ic2)1 6 3. (10a3)2

Write each equation in standard form.

60. — 6 (a0) 9


61. —4 ( y4) 2

66. y = 4x + 7

69. 3y - 5 = 6 (x + 2)
    67. y + 3 = 2(x - 5)
    70. x = 6 y + 3

Get Read y! To P r e p a r e f o r Le sso n 7 - 6 , d o Ex e r c i se s 7 2 - 7 7.

Se e Le sso n 7- 3.

61. ((9d)2)3


62. ((27t )5j2

Se e Le sso n 5- 5.

68. -3y + 6 :

9x

4

7x

Qv^2

71. 9y = x + 27

Describe the pattern for each sequence. Then write the next three numbers

in the sequence.

Se e Le sso n 4- 7.

72. 3, 6 , 9,...


73. 2, 7, 12,...
    73. 10, 4, - 2 ,...
    76. 3, - 1 , - 5 ,...

74 D i

2' 3' 4' ' - -

77. 1, 4, 9 ,...

452 Chapter 7 Exponents and Exponential Functions