| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.81 |
| Score | 0% | 56% |
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 |
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none of these is correct |
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a = -7 |
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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 \( \frac{45\sqrt{28}}{9\sqrt{4}} \)?
| 7 \( \sqrt{5} \) | |
| 5 \( \sqrt{7} \) | |
| \(\frac{1}{7}\) \( \sqrt{\frac{1}{5}} \) | |
| \(\frac{1}{5}\) \( \sqrt{\frac{1}{7}} \) |
To divide terms with radicals, divide the coefficients and radicands separately:
\( \frac{45\sqrt{28}}{9\sqrt{4}} \)
\( \frac{45}{9} \) \( \sqrt{\frac{28}{4}} \)
5 \( \sqrt{7} \)
What is \( 5 \)\( \sqrt{112} \) - \( 2 \)\( \sqrt{7} \)
| 3\( \sqrt{33} \) | |
| 18\( \sqrt{7} \) | |
| 10\( \sqrt{112} \) | |
| 3\( \sqrt{784} \) |
To subtract these radicals together their radicands must be the same:
5\( \sqrt{112} \) - 2\( \sqrt{7} \)
5\( \sqrt{16 \times 7} \) - 2\( \sqrt{7} \)
5\( \sqrt{4^2 \times 7} \) - 2\( \sqrt{7} \)
(5)(4)\( \sqrt{7} \) - 2\( \sqrt{7} \)
20\( \sqrt{7} \) - 2\( \sqrt{7} \)
Now that the radicands are identical, you can subtract them:
20\( \sqrt{7} \) - 2\( \sqrt{7} \)\({b + c \over a} = {b \over a} + {c \over a}\) defines which of the following?
commutative property for division |
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distributive 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, \({a^3 + 6a^2 \over a^2} = {a^3 \over a^2} + {6a^2 \over a^2} = a + 6\).
If a rectangle is twice as long as it is wide and has a perimeter of 12 meters, what is the area of the rectangle?
| 98 m2 | |
| 50 m2 | |
| 162 m2 | |
| 8 m2 |
The area of a rectangle is width (w) x height (h). In this problem we know that the rectangle is twice as long as it is wide so h = 2w. The perimeter of a rectangle is 2w + 2h and we know that the perimeter of this rectangle is 12 meters so the equation becomes: 2w + 2h = 12.
Putting these two equations together and solving for width (w):
2w + 2h = 12
w + h = \( \frac{12}{2} \)
w + h = 6
w = 6 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 6 - 2w
3w = 6
w = \( \frac{6}{3} \)
w = 2
Since h = 2w that makes h = (2 x 2) = 4 and the area = h x w = 2 x 4 = 8 m2