Beginning Algebra
Answer/Discussion to Practice
Problems
on Adding Real Numbers
 Answer/Discussion
to 1a
-15 + 7 |
| -15 + 7 = -8
The difference between 15 and 7 is 8 and the sign of 15 (the larger
absolute value) is -, that is how we get the answer of -8. |
| Answer/Discussion
to 1b
|
 |
*Mult. top and bottom of first fraction
by 2 to get the LCD of 10
*Add the numerators
and write over common denominator 10
|
| The sum of the absolute values would be 13/10 and their common sign
is -, that is how we get the answer of -13/10. |
| Answer/Discussion
to 1c
3.2 + (-1.3) + (- 4.1) |
 |
*3.2 + (-1.3) = 1.9
*1.9 + (-4.1) = -2.2 |
| Answer/Discussion
to 1d
|- 4 + (-3) + 2| |
 |
*- 4 + (-3) = -7
* - 7 + 2 = -5
*Evaluate the absolute value |
| Answer/Discussion
to 2a
1/2 |
| The opposite of 1/2 is -1/2, because both of these numbers have
the same absolute value, but are on opposite sides of the origin on the
number line. |
| Answer/Discussion
to 2b
-20 |
| The opposite of -20 is 20, because both of these numbers have
the same absolute value, but are on opposite sides of the origin on the
number line. |
| Answer/Discussion
to 3a
-(- 4) |
| Since the opposite of a negative is a positive, our answer is 4. |
| Answer/Discussion
to 3b
|
 |
*Evaluate the absolute value
|
All contents copyright (C) 2001 - 2008, WTAMU and Kim Seward. All rights reserved.
Last revised on Jan. 8, 2002 by Kim Seward. |
