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hendricks_beginning_algebra_1e_ch1_3

54 Chapter 1 Real Numbers and Algebraic Expressions 3c. The complement of a 25° angle is The supplement of a 25° angle is 90° - 25° = 65° 180° - 25° = 155° 25° 65° 25° 155° Student Check 3 Write a mathematical expression that represents the given situation and then find the result. a. The highest point on Earth is the peak of Mount Everest in the Himalaya Mountains. The peak is 29,028 ft above sea level. The lowest point on land is the Dead Sea at 1312 ft below sea level. What is the difference in these altitudes? b. Find the measure of the unknown angle of the given triangle. 45° 100° c c. Find the complement and the supplement of an angle whose measure is 85°. Troubleshooting Common Errors A common error associated with subtracting real numbers is shown. �� ������������������������ ���������������� A problem and an incorrect solution is given. Provide the correct solution and an explanation of the error. -8 - 2 �������������������������������������� ���������������������������������������������������������������� We first convert the problem to an addition problem. Since the numbers being added have the same signs, we add their absolute values and keep the sign. -8 - 2 = -8 + (-2) = -10 Objective 4 ▶ Troubleshoot common errors. -8 - 2 = -6 ANSWERS TO STUDENT CHECKS Student Check 1 a. -3 b. 15.6 c. -90 d. -24 e. - 5 12 Student Check 2 a. 5 b. -18 c. -3 Student Check 3 a. 30,340 b. 35° c. 5°, 95° SUMMARY OF KEY CONCEPTS 1. Subtracting real numbers is equivalent to adding the opposite of a number. 2. We can apply the order of operations to simplify expressions that involve adding and subtracting real numbers. 2


hendricks_beginning_algebra_1e_ch1_3
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