| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
Solve for \( \frac{4!}{5!} \)
| 7 | |
| \( \frac{1}{1680} \) | |
| 15120 | |
| \( \frac{1}{5} \) |
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:
\( \frac{4!}{5!} \)
\( \frac{4 \times 3 \times 2 \times 1}{5 \times 4 \times 3 \times 2 \times 1} \)
\( \frac{1}{5} \)
\( \frac{1}{5} \)
4! = ?
4 x 3 x 2 x 1 |
|
3 x 2 x 1 |
|
4 x 3 |
|
5 x 4 x 3 x 2 x 1 |
A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.
Convert b-3 to remove the negative exponent.
| \( \frac{1}{b^3} \) | |
| \( \frac{-1}{-3b^{3}} \) | |
| \( \frac{-1}{-3b} \) | |
| \( \frac{-1}{b^{-3}} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.
What is \( \frac{1}{7} \) ÷ \( \frac{3}{7} \)?
| \(\frac{1}{3}\) | |
| \(\frac{1}{14}\) | |
| \(\frac{1}{63}\) | |
| 2\(\frac{1}{3}\) |
To divide fractions, invert the second fraction and then multiply:
\( \frac{1}{7} \) ÷ \( \frac{3}{7} \) = \( \frac{1}{7} \) x \( \frac{7}{3} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{1}{7} \) x \( \frac{7}{3} \) = \( \frac{1 x 7}{7 x 3} \) = \( \frac{7}{21} \) = \(\frac{1}{3}\)
What is \( 5 \)\( \sqrt{75} \) + \( 2 \)\( \sqrt{3} \)
| 27\( \sqrt{3} \) | |
| 10\( \sqrt{3} \) | |
| 7\( \sqrt{3} \) | |
| 10\( \sqrt{25} \) |
To add these radicals together their radicands must be the same:
5\( \sqrt{75} \) + 2\( \sqrt{3} \)
5\( \sqrt{25 \times 3} \) + 2\( \sqrt{3} \)
5\( \sqrt{5^2 \times 3} \) + 2\( \sqrt{3} \)
(5)(5)\( \sqrt{3} \) + 2\( \sqrt{3} \)
25\( \sqrt{3} \) + 2\( \sqrt{3} \)
Now that the radicands are identical, you can add them together:
25\( \sqrt{3} \) + 2\( \sqrt{3} \)