Your Results | Global Average | |
---|---|---|
Questions | 5 | 5 |
Correct | 0 | 3.15 |
Score | 0% | 63% |
What is \( 3 \)\( \sqrt{63} \) + \( 8 \)\( \sqrt{7} \)
11\( \sqrt{9} \) | |
24\( \sqrt{441} \) | |
17\( \sqrt{7} \) | |
24\( \sqrt{9} \) |
To add these radicals together their radicands must be the same:
3\( \sqrt{63} \) + 8\( \sqrt{7} \)
3\( \sqrt{9 \times 7} \) + 8\( \sqrt{7} \)
3\( \sqrt{3^2 \times 7} \) + 8\( \sqrt{7} \)
(3)(3)\( \sqrt{7} \) + 8\( \sqrt{7} \)
9\( \sqrt{7} \) + 8\( \sqrt{7} \)
Now that the radicands are identical, you can add them together:
9\( \sqrt{7} \) + 8\( \sqrt{7} \)Which of these numbers is a factor of 24?
14 | |
26 | |
4 | |
27 |
The factors of a number are all positive integers that divide evenly into the number. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24.
What is \( \frac{2}{7} \) ÷ \( \frac{3}{8} \)?
\(\frac{2}{25}\) | |
2\(\frac{2}{7}\) | |
\(\frac{2}{45}\) | |
\(\frac{16}{21}\) |
To divide fractions, invert the second fraction and then multiply:
\( \frac{2}{7} \) ÷ \( \frac{3}{8} \) = \( \frac{2}{7} \) x \( \frac{8}{3} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{2}{7} \) x \( \frac{8}{3} \) = \( \frac{2 x 8}{7 x 3} \) = \( \frac{16}{21} \) = \(\frac{16}{21}\)
If \(\left|a\right| = 7\), which of the following best describes a?
a = -7 |
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a = 7 |
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none of these is correct |
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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 the least common multiple of 6 and 10?
29 | |
30 | |
9 | |
34 |
The first few multiples of 6 are [6, 12, 18, 24, 30, 36, 42, 48, 54, 60] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [30, 60, 90] making 30 the smallest multiple 6 and 10 have in common.