| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.92 |
| Score | 0% | 58% |
What is \( \frac{2}{8} \) - \( \frac{5}{10} \)?
| 2 \( \frac{8}{40} \) | |
| \( \frac{9}{40} \) | |
| -\(\frac{1}{4}\) | |
| 1 \( \frac{5}{40} \) |
To subtract these fractions, first find the lowest common multiple of their denominators. The first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80] and the first few multiples of 10 are [10, 20, 30, 40, 50, 60, 70, 80, 90]. The first few multiples they share are [40, 80] making 40 the smallest multiple 8 and 10 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{2 x 5}{8 x 5} \) - \( \frac{5 x 4}{10 x 4} \)
\( \frac{10}{40} \) - \( \frac{20}{40} \)
Now, because the fractions share a common denominator, you can subtract them:
\( \frac{10 - 20}{40} \) = \( \frac{-10}{40} \) = -\(\frac{1}{4}\)
\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
distributive property for division |
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commutative property for division |
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commutative property for multiplication |
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distributive property for multiplication |
The distributive property for division helps in solving expressions like \({b + c \over a}\). It specifies that the result of dividing a fraction with multiple terms in the numerator and one term in the denominator can be obtained by dividing each term individually and then totaling the results: \({b + c \over a} = {b \over a} + {c \over a}\). For example, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).
Which of these numbers is a factor of 20?
| 16 | |
| 10 | |
| 4 | |
| 2 |
The factors of a number are all positive integers that divide evenly into the number. The factors of 20 are 1, 2, 4, 5, 10, 20.
What is \( 3 \)\( \sqrt{175} \) - \( 8 \)\( \sqrt{7} \)
| -5\( \sqrt{25} \) | |
| -5\( \sqrt{7} \) | |
| -5\( \sqrt{24} \) | |
| 7\( \sqrt{7} \) |
To subtract these radicals together their radicands must be the same:
3\( \sqrt{175} \) - 8\( \sqrt{7} \)
3\( \sqrt{25 \times 7} \) - 8\( \sqrt{7} \)
3\( \sqrt{5^2 \times 7} \) - 8\( \sqrt{7} \)
(3)(5)\( \sqrt{7} \) - 8\( \sqrt{7} \)
15\( \sqrt{7} \) - 8\( \sqrt{7} \)
Now that the radicands are identical, you can subtract them:
15\( \sqrt{7} \) - 8\( \sqrt{7} \)Convert c-5 to remove the negative exponent.
| \( \frac{-1}{-5c^{5}} \) | |
| \( \frac{-1}{-5c} \) | |
| \( \frac{-5}{-c} \) | |
| \( \frac{1}{c^5} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.