| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.59 |
| Score | 0% | 72% |
If \( \left|b + 9\right| \) + 8 = -6, which of these is a possible value for b?
| -20 | |
| -11 | |
| -1 | |
| -23 |
First, solve for \( \left|b + 9\right| \):
\( \left|b + 9\right| \) + 8 = -6
\( \left|b + 9\right| \) = -6 - 8
\( \left|b + 9\right| \) = -14
The value inside the absolute value brackets can be either positive or negative so (b + 9) must equal - 14 or --14 for \( \left|b + 9\right| \) to equal -14:
| b + 9 = -14 b = -14 - 9 b = -23 | b + 9 = 14 b = 14 - 9 b = 5 |
So, b = 5 or b = -23.
If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
|
a = 7 |
|
a = 7 or a = -7 |
|
none of these is correct |
The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).
How many hours does it take a car to travel 50 miles at an average speed of 25 miles per hour?
| 3 hours | |
| 2 hours | |
| 8 hours | |
| 1 hour |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Solving for time:
time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{50mi}{25mph} \)
2 hours
Which of the following is not an integer?
1 |
|
\({1 \over 2}\) |
|
0 |
|
-1 |
An integer is any whole number, including zero. An integer can be either positive or negative. Examples include -77, -1, 0, 55, 119.
A menswear store is having a sale: "Buy one shirt at full price and get another shirt for 40% off." If Frank buys two shirts, each with a regular price of $16, how much money will he save?
| $6.40 | |
| $3.20 | |
| $8.00 | |
| $4.80 |
By buying two shirts, Frank will save $16 x \( \frac{40}{100} \) = \( \frac{$16 x 40}{100} \) = \( \frac{$640}{100} \) = $6.40 on the second shirt.