| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.82 |
| Score | 0% | 56% |
What is 4\( \sqrt{6} \) x 9\( \sqrt{7} \)?
| 36\( \sqrt{42} \) | |
| 13\( \sqrt{6} \) | |
| 13\( \sqrt{42} \) | |
| 13\( \sqrt{7} \) |
To multiply terms with radicals, multiply the coefficients and radicands separately:
4\( \sqrt{6} \) x 9\( \sqrt{7} \)
(4 x 9)\( \sqrt{6 \times 7} \)
36\( \sqrt{42} \)
What is \( 7 \)\( \sqrt{63} \) - \( 4 \)\( \sqrt{7} \)
| 28\( \sqrt{9} \) | |
| 28\( \sqrt{63} \) | |
| 28\( \sqrt{7} \) | |
| 17\( \sqrt{7} \) |
To subtract these radicals together their radicands must be the same:
7\( \sqrt{63} \) - 4\( \sqrt{7} \)
7\( \sqrt{9 \times 7} \) - 4\( \sqrt{7} \)
7\( \sqrt{3^2 \times 7} \) - 4\( \sqrt{7} \)
(7)(3)\( \sqrt{7} \) - 4\( \sqrt{7} \)
21\( \sqrt{7} \) - 4\( \sqrt{7} \)
Now that the radicands are identical, you can subtract them:
21\( \sqrt{7} \) - 4\( \sqrt{7} \)If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
|
a = 7 or a = -7 |
|
a = 7 |
|
none of these is correct |
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 \( \frac{1}{9} \) x \( \frac{1}{7} \)?
| \(\frac{1}{8}\) | |
| \(\frac{1}{27}\) | |
| \(\frac{1}{63}\) | |
| \(\frac{1}{9}\) |
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{1}{9} \) x \( \frac{1}{7} \) = \( \frac{1 x 1}{9 x 7} \) = \( \frac{1}{63} \) = \(\frac{1}{63}\)
What is \( \frac{3b^5}{7b^3} \)?
| 2\(\frac{1}{3}\)b8 | |
| \(\frac{3}{7}\)b2 | |
| \(\frac{3}{7}\)b\(\frac{3}{5}\) | |
| \(\frac{3}{7}\)b1\(\frac{2}{3}\) |
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:
\( \frac{3b^5}{7b^3} \)
\( \frac{3}{7} \) b(5 - 3)
\(\frac{3}{7}\)b2