Intermediate Algebra (11th edition)

Sea level refers to the surface of the ocean. The depth of a body of water such as an ocean or
sea can be expressed as a negative number, representing average depth in feet below sea level.
By contrast, the altitude of a mountain can be expressed as a positive number, indicating its
height in feet above sea level. The table gives selected depths and heights.

SECTION 1.1 Basic Concepts 13

Source: World Almanac and Book of Facts.

Average Depth in Feet Altitude in Feet

Body of Water (as a negative number) Mountain (as a positive number)

Pacific Ocean McKinley 20,320

South China Sea Point Success 14,158

Gulf of California Matlalcueyetl 14,636

Caribbean Sea Rainier 14,410

Indian Ocean -12,598 Steele 16,644

• 8,448


• 2,375


• 4,802


• 12,925

61.List the bodies of water in order, starting with the deepest and ending with the shallowest.

62.List the mountains in order, starting with the shortest and ending with the tallest.

63.Trueor false: The absolute value of the depth of the Pacific Ocean is greater than the

absolute value of the depth of the Indian Ocean.

64.Trueor false: The absolute value of the depth of the Gulf of California is greater than

the absolute value of the depth of the Caribbean Sea.

Use the number line to answer trueor falseto each statement. See Example 7.

–6–5–4–3–2–1 0 1 2 3 4 5 6

Rewrite each statement with so that it uses instead. Rewrite each statement with so
that it uses. See Example 7.

Use an inequality symbol to write each statement. See Example 8.

81.7 is greater than y. 82. is less than 10.

83.5 is greater than or equal to 5. 84. is less than or equal to.

85. is less than or equal to 10. 86. is greater than or equal to 21.


86. is not equal to 0. 88. is not equal to.
    89.tis between and 5. 90.ris between and 12.


87. 3 xis between and 4, including 92. 6 xis between and 6, excluding
    and excluding 4. and including 6.

Simplify. Then tell whether the resulting statement is trueor false. See Example 8.

Write each set in interval notation and graph the interval. See Examples 9–11.

101. 
     
     
     
     102. 
          
          
          
          103. 
               
          
          
          
          
     
     
     
     


102. 5 x |xÚ- 36 105. 5 x | 06 x 6 3.5 6 106. 5 x |- 46 x 6 6.1 6

5 x |x7- 16 5 x |x 656 5 x |x... 66

- 8 7-|- 6 | - 10 7-|- 4 |

8 + 7 ... 3 # 5 - |- 3 |Ú- 3 - |- 4 |...- 4

• 667 + 3 - 764 + 1 2 # 5 Ú 4 + 6

- 3 - 3 - 2 - 2

- 3 - 5

5 x+ 3 6 x+ 7 - 9

3 t- 4 5 x+ 4

- 6 - 6

- 4

• 5 7- 10 - 7 7- 12 06 x - 36 x

672 571 - 964 - 661

7

7 6 6

3 7- 2 6 7- 3 - 3 Ú- 3 - 5 ...- 5

- 6 6- 1 - 4 6- 2 - 4 7- 3 - 3 7- 1