Easy Algebra Step-by-Step

Computation with Real Numbers 17

Step 2. Compare the absolute values.

− 60 has the greater absolute value because 60 > 35.

c. −^2

9

7

9

,

Step 1. Determine the absolute values.

−= =

2

9

2

9

7

9

7

9

,

Step 2. Compare the absolute values.

7

9

has the greater absolute value because

7

9

2

9

>.

d.

2

9

7

9

, −

Step 1. Determine the absolute values.

2

9

2

9

7

9

7

9

=−, =

Step 2. Compare the absolute values.

−

7

9

has the greater absolute value because

7

9

2

9

>.

Addition and Subtraction of Signed Numbers

Real numbers are called signed numbers because these numbers may be posi-

tive, negative, or 0. From your knowledge of arithmetic, you already know how

to do addition, subtraction, multiplication, and division with positive numbers

and 0. To do these operations with all signed numbers, you simply use the

absolute values of the numbers and follow these eight rules.

Addition of Signed Numbers

Rule 1. To add two numbers that have the same sign, add their absolute

values and give the sum their common sign.

P

Don’t make the mistake of trying

to compare the numbers without

fi rst fi nding the absolute values.