| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.80 |
| Score | 0% | 56% |
What is \( \frac{-9z^9}{5z^4} \)?
| -1\(\frac{4}{5}\)z13 | |
| -1\(\frac{4}{5}\)z36 | |
| -\(\frac{5}{9}\)z5 | |
| -1\(\frac{4}{5}\)z5 |
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:
\( \frac{-9z^9}{5z^4} \)
\( \frac{-9}{5} \) z(9 - 4)
-1\(\frac{4}{5}\)z5
A machine in a factory has an error rate of 8 parts per 100. The machine normally runs 24 hours a day and produces 6 parts per hour. Yesterday the machine was shut down for 7 hours for maintenance.
How many error-free parts did the machine produce yesterday?
| 138.2 | |
| 149.4 | |
| 93.8 | |
| 97.6 |
The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:
\( \frac{8}{100} \) x 6 = \( \frac{8 \times 6}{100} \) = \( \frac{48}{100} \) = 0.48 errors per hour
So, in an average hour, the machine will produce 6 - 0.48 = 5.52 error free parts.
The machine ran for 24 - 7 = 17 hours yesterday so you would expect that 17 x 5.52 = 93.8 error free parts were produced yesterday.
What is the greatest common factor of 80 and 56?
| 8 | |
| 39 | |
| 52 | |
| 42 |
The factors of 80 are [1, 2, 4, 5, 8, 10, 16, 20, 40, 80] and the factors of 56 are [1, 2, 4, 7, 8, 14, 28, 56]. They share 4 factors [1, 2, 4, 8] making 8 the greatest factor 80 and 56 have in common.
What is \( 3 \)\( \sqrt{28} \) + \( 5 \)\( \sqrt{7} \)
| 15\( \sqrt{7} \) | |
| 15\( \sqrt{28} \) | |
| 8\( \sqrt{4} \) | |
| 11\( \sqrt{7} \) |
To add these radicals together their radicands must be the same:
3\( \sqrt{28} \) + 5\( \sqrt{7} \)
3\( \sqrt{4 \times 7} \) + 5\( \sqrt{7} \)
3\( \sqrt{2^2 \times 7} \) + 5\( \sqrt{7} \)
(3)(2)\( \sqrt{7} \) + 5\( \sqrt{7} \)
6\( \sqrt{7} \) + 5\( \sqrt{7} \)
Now that the radicands are identical, you can add them together:
6\( \sqrt{7} \) + 5\( \sqrt{7} \)\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
distributive property for division |
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commutative property for multiplication |
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commutative property for division |
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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, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).