Algebra Demystified 2nd Ed

84 algebra De mystif ieD

DeMYSTiFieD / algebra DeMYSTiFieD / HuttenMuller / 000-0 / Chapter 4

7. –x – (–14) = –x + 14


8. –x – 9 = –x + (–9)


9. −^4 +=
   5

2

3

− (^4) ⋅+⋅=− +=−+=−
5
3
3
2
3
5
5
12
15
10
15
12 10
15
2
15

10. 2381 −=^1417
    8

13

4

17

8

13

4

2

2

17

8

26

8

17 26

8

9

8

−=−⋅=−= − =−

11. −−= 4129 21 −^38 −=− ⋅−⋅=− −=−−=−
    9

3

2

38

9

2

2

3

2

9

9

76

18

27

18

76 27

18

103

188

12.^5
36

−= 2 5

36

2

1

36

36

5

36

72

36

572

36

67

36

−⋅ =−=− =−

13.^6
25

2

3

14

15

+− =^6

25

3

3

2

3

25

25

14

15

5

5

18

75

50

75

70

75

18 50 70

7

⋅+⋅−⋅= +−= +−

55

2

75

=−

14. −^4 +− =
    3

5

6

8

21

− (^4) ⋅+⋅− ⋅=− +−=−+−
3
14
14
5
6
7
7
8
21
2
2
56
42
35
42
16
42
56 35 16
442
37
42
=−

15.^1345 −− 21 167 =^9
5

7

2

13

7

9

5

14

14

7

2

35

35

13

7

10

10

126 245 130

7

−− =⋅ −⋅ −⋅= −−

00

249

70

=−

Multiplication and Division with Negative Numbers

When taking the product of two or more quantities when one or more of them

is negative, we take the product as if the negative signs were not there. An even

number of negative factors gives us a positive product and an odd number of

negative factors gives us a negative product. Similarly, for a quotient (or fraction),

two negative numbers give us a positive quotient, and one negative number and

one positive number gives us a negative quotient. The rules for multiplying or

dividing negative numbers are below.

()()

()()

()

()()

−−=

−=−=−

÷− =− ÷

−÷−=

abab

ab ab ab

abab

abaab÷