| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.18 |
| Score | 0% | 64% |
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 or a = -7 |
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a = -7 |
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none of these is correct |
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a = 7 |
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).
What is \( 2 \)\( \sqrt{12} \) + \( 6 \)\( \sqrt{3} \)
| 12\( \sqrt{4} \) | |
| 12\( \sqrt{36} \) | |
| 8\( \sqrt{12} \) | |
| 10\( \sqrt{3} \) |
To add these radicals together their radicands must be the same:
2\( \sqrt{12} \) + 6\( \sqrt{3} \)
2\( \sqrt{4 \times 3} \) + 6\( \sqrt{3} \)
2\( \sqrt{2^2 \times 3} \) + 6\( \sqrt{3} \)
(2)(2)\( \sqrt{3} \) + 6\( \sqrt{3} \)
4\( \sqrt{3} \) + 6\( \sqrt{3} \)
Now that the radicands are identical, you can add them together:
4\( \sqrt{3} \) + 6\( \sqrt{3} \)A triathlon course includes a 500m swim, a 50.6km bike ride, and a 8.100000000000001km run. What is the total length of the race course?
| 49.7km | |
| 59.2km | |
| 31.7km | |
| 39.4km |
To add these distances, they must share the same unit so first you need to first convert the swim distance from meters (m) to kilometers (km) before adding it to the bike and run distances which are already in km. To convert 500 meters to kilometers, divide the distance by 1000 to get 0.5km then add the remaining distances:
total distance = swim + bike + run
total distance = 0.5km + 50.6km + 8.100000000000001km
total distance = 59.2km
What is (a4)3?
| a | |
| 3a4 | |
| a-1 | |
| a12 |
To raise a term with an exponent to another exponent, retain the base and multiply the exponents:
(a4)3What is 2a2 + 5a2?
| 7a-4 | |
| 7a2 | |
| -3a2 | |
| 3a2 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:
2a2 + 5a2
(2 + 5)a2
7a2