Adding Real Numbers
ALGEBRA 1 LESSON 1-4
pages 27–30 Exercises
1
6
24. – 13
14
1. 6 + (–3); 3
12. –42
2. –1 + (–2); –3
13. 2.2
3. –5 + 7; 2
14. –0.65
4. 3 + (–4); –1
15. –7.49
25. –47 + 12 = –35, 35 ft
below the surface
5. 15
16. 1.33
26. 8 + (–5) = 3, 3 yd gain
6. –11
17. 14
27. –6 + 13 = 7, 7°F
7. –19
8. 12.14
9. –4
10. 5
11. –8
23. 5
15
18. – 8
9
19. 6 3
16
20. –6 1
8
28. 8.7
29. –1.7
30. 1.7
31. –8.7
21. 0
32. 12.6
22. – 13
18
1-4
Adding Real Numbers
ALGEBRA 1 LESSON 1-4
33. –5.6
38.
34. 5.6
35. –12.6
39.
36–37. Choices of variable may vary.
36. c = change in temp., –8 + c
–1
–21
40.
37. c = change in amount
of money, 74 + c
41.
7
43. –13
b. $45
44. 6.6
1-4
50. –1.72
– 1
a. $92
c. $27
49. –20.83
22
42. –2.7
46. 4
48. –18.53
1.8
2
24
35
0
25
–12
b. –11°F
45. 11 19
47. –3 22
–18.2
11.6
19.1
a. –1°F
c. 11°F
1.4
23.2
51. – 17
60
52. –5 11
120
53. 0.8
54. 4 1
3
55. –8.8
Adding Real Numbers
ALGEBRA 1 LESSON 1-4
56. 13.8 million people
65. 5
72. –0.6
57. 6.3 million people
66. –1
73. 8.7
58. Weaving; add the
numbers in each column.
67. 1
74. 0.1
68. The sum of –227 and 319;
the sum of –227 and 319
is positive, while the sum
of 227 and –319 is negative.
75. –1.9
59. a. 100 = 50
442
221
b. 0.23
c. about 23%
62. 1
69. Answers may vary. Sample:
Although 20 and –20 are
opposite numbers, there is
no such thing as opposite
temperatures.
63. –5
70. –0.3
64. 7
71. –13.7
60. 0
61. –2
1-4
76. +2
Adding Real Numbers
ALGEBRA 1 LESSON 1-4
77. Answers may vary. Sample: 80. (continued)
b. 13 5
2 0
1
–1 3 0.5
18 4
6
78. The matrices are not the
same size, so they can’t
be added.
79. No; time and temperature
are different quantities and
can’t be added.
80. a.
8
10
4
3
2
1
5
2
0
1
1
1
5
8
2
2
2
1
1
0
0
1
1
1
2
82. a. 4
6
2
0
2
2
2
c. 4 employees
d. 10 employees
e. Answers may vary. Sample:
Multiply the entries in each
column by the appropriate
hourly wage, then by 8, and
then add all entries to find
the total wages.
f. $3230
81. $7
1-4
b. –4
Adding Real Numbers
ALGEBRA 1 LESSON 1-4
83.
11
4
21
2
84.
81
2
20
85. w
86.
87.
88.
89.
10
–c
2
58a
21
– 2b
9
x
12
–1
90. – x
1
2
96. Pos.; if m is neg.,
–m is pos. and the
sum of two pos.
is pos.
12
91. t
1
32
–27
61
0
2
6
92. –3m + 1
4
93. m
9
97. Zero; sum of neg.
and pos. is the
94. Pos.; if m is neg.,
difference of the
abs. values.
–m is pos. and the
|n| = |m| so |n| – |m| = 0.
sum of two pos.
is pos.
98. zero; n + (–m) = n + (–n) = 0
95. Neg.; if n is pos.,
103. C 107. < 111. 9
–n is neg. and the 99. B
sum of two neg.
100. F 104. H 108. > 112. 2.2
is neg.
101. D 105. < 109. > 113. 18
102. F
1-4
106. =
110. = 114. 21