| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
What is the distance in miles of a trip that takes 4 hours at an average speed of 45 miles per hour?
| 200 miles | |
| 180 miles | |
| 50 miles | |
| 160 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 = \( 45mph \times 4h \)
180 miles
What is \( \frac{2}{8} \) ÷ \( \frac{1}{7} \)?
| 1\(\frac{3}{4}\) | |
| \(\frac{1}{14}\) | |
| 14 | |
| \(\frac{2}{35}\) |
To divide fractions, invert the second fraction and then multiply:
\( \frac{2}{8} \) ÷ \( \frac{1}{7} \) = \( \frac{2}{8} \) x \( \frac{7}{1} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{2}{8} \) x \( \frac{7}{1} \) = \( \frac{2 x 7}{8 x 1} \) = \( \frac{14}{8} \) = 1\(\frac{3}{4}\)
What is 4\( \sqrt{8} \) x 2\( \sqrt{2} \)?
| 8\( \sqrt{2} \) | |
| 32 | |
| 6\( \sqrt{2} \) | |
| 6\( \sqrt{16} \) |
To multiply terms with radicals, multiply the coefficients and radicands separately:
4\( \sqrt{8} \) x 2\( \sqrt{2} \)
(4 x 2)\( \sqrt{8 \times 2} \)
8\( \sqrt{16} \)
Now we need to simplify the radical:
8\( \sqrt{16} \)
8\( \sqrt{4^2} \)
(8)(4)
32
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 |
|
none of these is correct |
|
a = -7 |
|
a = 7 or 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 \( \frac{-8c^6}{4c^2} \)?
| -2c-4 | |
| -2c4 | |
| -\(\frac{1}{2}\)c-4 | |
| -\(\frac{1}{2}\)c8 |
To divide terms with exponents, the base of both exponents must be the same. In this case they are so divide the coefficients and subtract the exponents:
\( \frac{-8c^6}{4c^2} \)
\( \frac{-8}{4} \) c(6 - 2)
-2c4