| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.24 |
| Score | 0% | 65% |
What is the distance in miles of a trip that takes 7 hours at an average speed of 25 miles per hour?
| 175 miles | |
| 495 miles | |
| 280 miles | |
| 75 miles |
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 distance:
distance = \( \text{speed} \times \text{time} \)
distance = \( 25mph \times 7h \)
175 miles
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 or a = -7 |
|
none of these is correct |
|
a = 7 |
|
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 \( 2 \)\( \sqrt{175} \) + \( 2 \)\( \sqrt{7} \)
| 4\( \sqrt{7} \) | |
| 4\( \sqrt{25} \) | |
| 4\( \sqrt{175} \) | |
| 12\( \sqrt{7} \) |
To add these radicals together their radicands must be the same:
2\( \sqrt{175} \) + 2\( \sqrt{7} \)
2\( \sqrt{25 \times 7} \) + 2\( \sqrt{7} \)
2\( \sqrt{5^2 \times 7} \) + 2\( \sqrt{7} \)
(2)(5)\( \sqrt{7} \) + 2\( \sqrt{7} \)
10\( \sqrt{7} \) + 2\( \sqrt{7} \)
Now that the radicands are identical, you can add them together:
10\( \sqrt{7} \) + 2\( \sqrt{7} \)Solve for \( \frac{3!}{4!} \)
| 56 | |
| \( \frac{1}{4} \) | |
| 1680 | |
| 6720 |
A factorial is the product of an integer and all the positive integers below it. To solve a fraction featuring factorials, expand the factorials and cancel out like numbers:
\( \frac{3!}{4!} \)
\( \frac{3 \times 2 \times 1}{4 \times 3 \times 2 \times 1} \)
\( \frac{1}{4} \)
\( \frac{1}{4} \)
Convert y-5 to remove the negative exponent.
| \( \frac{5}{y} \) | |
| \( \frac{1}{y^5} \) | |
| \( \frac{-5}{y} \) | |
| \( \frac{1}{y^{-5}} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.