Page 85 - MarceAlgebra Demystified

72 CHAPTER 4 Negative Numbers

6 2 14 6 3 2 25 14 5 18 50 70
5: þ ¼ þ ¼ þ
25 3 15 25 3 3 25 15 5 75 75 75
18 þ 50 70 2
¼ ¼
75 75
4 5 8 4 14 5 7 8 2 56 35 16
6: þ ¼ þ ¼ þ
3 6 21 3 14 6 7 21 2 42 42 42
56 þ 35 16 37
¼ ¼
42 42
9 7 13 9 14 7 35 13 10
4 1 6
7: 1 3 1 ¼ ¼
5 2 7 5 2 7 5 14 2 35 7 10
126 245 130 249
¼ ¼
70 70

Multiplication and Division with Negative

Numbers

When taking the product of two or more quantities when one or more of
them is negative, take the product as you ordinarily would as if the negative
signs were not there. Count the number of negatives in the product. An even
number of negative signs will yield a positive product and an odd number of
negative signs will yield a negative product. Similarly, for a quotient (or
fraction), two negatives yield a positive quotient and one negative and one
positive yield a negative quotient.

Examples

ð4Þð 3Þð2Þ¼ 24 ð 5Þð 6Þð 1Þð3Þ¼ 90 8 ð 2Þ¼ 4
55 2 2
¼ 11 ¼
5 3 3

Practice

1: ð15Þð 2Þ¼