Page 52

hendricks_beginning_algebra_1e_ch1_3

50 Chapter 1 Real Numbers and Algebraic Expressions �� ������������������������ Subtraction of Real Numbers The world’s coldest recorded temperature is -129°F in Vostok, Antarctica. The world’s hottest recorded temperature is 134°F in Death Valley, California. What is the difference between the hottest and coldest temperatures? To answer this question, we must know how to subtract real numbers. Subtracting Real Numbers To understand how to subtract two real numbers, consider the following expressions. 7 - 2 = 5 7 + (-2) = 5 These two expressions are equivalent, which indicates that subtraction is really a form of addition. Subtraction is equivalent to adding the opposite of a number. �������������������� Subtraction of Real Numbers For all real numbers a and b, a - b = a + (-b) ���������������������� Subtracting Real Numbers Step 1: Rewrite the expression by adding the opposite of the second number. Step 2: Use the rules for addition to simplify the expression. �� ������������������������ ������������������ Perform the indicated operation. 1a. -6 - 2 1b. 3.5 - (-2.5) 1c. 5 - 12 1d. -100 - (-25) 1e. - 1 2 - 3 5 Solutions 1a. -6 - 2 = -6 + (-2) Rewrite as adding the opposite of 2, which is -2. = -8 Add the numbers. 1b. 3.5 - (-2.5) = 3.5 + (2.5) Rewrite as adding the opposite of -2.5, which is 2.5. = 6 Add the numbers. 1c. 5 - 12 = 5 + (-12) Rewrite as adding the opposite of 12, which is -12. = -7 Add the numbers. 1d. -100 - (-25) = -100 + (25) Rewrite as adding the opposite of -25, which is 25. = -75 Add the numbers. ▶ OBJECTIVES As a result of completing this section, you will be able to 1. Subtract real numbers. 2. Apply the order of operations. 3. Solve real-life problems. 4. Troubleshoot common errors. Objective 1 ▶ Subtract two real numbers.


hendricks_beginning_algebra_1e_ch1_3
To see the actual publication please follow the link above