| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.33 |
| Score | 0% | 67% |
If a car travels 45 miles in 3 hours, what is the average speed?
| 75 mph | |
| 20 mph | |
| 55 mph | |
| 15 mph |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)What is \( 8 \)\( \sqrt{20} \) + \( 5 \)\( \sqrt{5} \)
| 40\( \sqrt{20} \) | |
| 13\( \sqrt{5} \) | |
| 21\( \sqrt{5} \) | |
| 40\( \sqrt{5} \) |
To add these radicals together their radicands must be the same:
8\( \sqrt{20} \) + 5\( \sqrt{5} \)
8\( \sqrt{4 \times 5} \) + 5\( \sqrt{5} \)
8\( \sqrt{2^2 \times 5} \) + 5\( \sqrt{5} \)
(8)(2)\( \sqrt{5} \) + 5\( \sqrt{5} \)
16\( \sqrt{5} \) + 5\( \sqrt{5} \)
Now that the radicands are identical, you can add them together:
16\( \sqrt{5} \) + 5\( \sqrt{5} \)Simplify \( \sqrt{50} \)
| 4\( \sqrt{4} \) | |
| 5\( \sqrt{2} \) | |
| 5\( \sqrt{4} \) | |
| 6\( \sqrt{4} \) |
To simplify a radical, factor out the perfect squares:
\( \sqrt{50} \)
\( \sqrt{25 \times 2} \)
\( \sqrt{5^2 \times 2} \)
5\( \sqrt{2} \)
Which of the following is not an integer?
\({1 \over 2}\) |
|
1 |
|
-1 |
|
0 |
An integer is any whole number, including zero. An integer can be either positive or negative. Examples include -77, -1, 0, 55, 119.
What is 2y3 - 7y3?
| 9y9 | |
| 9y3 | |
| -5y3 | |
| 5y3 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so subtract the coefficients and retain the base and exponent:
2y3 - 7y3
(2 - 7)y3
-5y3