| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
If a rectangle is twice as long as it is wide and has a perimeter of 24 meters, what is the area of the rectangle?
| 98 m2 | |
| 50 m2 | |
| 162 m2 | |
| 32 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 24 meters so the equation becomes: 2w + 2h = 24.
Putting these two equations together and solving for width (w):
2w + 2h = 24
w + h = \( \frac{24}{2} \)
w + h = 12
w = 12 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 12 - 2w
3w = 12
w = \( \frac{12}{3} \)
w = 4
Since h = 2w that makes h = (2 x 4) = 8 and the area = h x w = 4 x 8 = 32 m2
What is \( 3 \)\( \sqrt{27} \) - \( 4 \)\( \sqrt{3} \)
| -1\( \sqrt{81} \) | |
| -1\( \sqrt{0} \) | |
| -1\( \sqrt{9} \) | |
| 5\( \sqrt{3} \) |
To subtract these radicals together their radicands must be the same:
3\( \sqrt{27} \) - 4\( \sqrt{3} \)
3\( \sqrt{9 \times 3} \) - 4\( \sqrt{3} \)
3\( \sqrt{3^2 \times 3} \) - 4\( \sqrt{3} \)
(3)(3)\( \sqrt{3} \) - 4\( \sqrt{3} \)
9\( \sqrt{3} \) - 4\( \sqrt{3} \)
Now that the radicands are identical, you can subtract them:
9\( \sqrt{3} \) - 4\( \sqrt{3} \)In a class of 24 students, 9 are taking German and 10 are taking Spanish. Of the students studying German or Spanish, 2 are taking both courses. How many students are not enrolled in either course?
| 19 | |
| 7 | |
| 20 | |
| 12 |
The number of students taking German or Spanish is 9 + 10 = 19. Of that group of 19, 2 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 19 - 2 = 17 who are taking at least one language. 24 - 17 = 7 students who are not taking either language.
Simplify \( \frac{24}{56} \).
| \( \frac{4}{7} \) | |
| \( \frac{7}{19} \) | |
| \( \frac{2}{3} \) | |
| \( \frac{3}{7} \) |
To simplify this fraction, first find the greatest common factor between them. The factors of 24 are [1, 2, 3, 4, 6, 8, 12, 24] and the factors of 56 are [1, 2, 4, 7, 8, 14, 28, 56]. They share 4 factors [1, 2, 4, 8] making 8 their greatest common factor (GCF).
Next, divide both numerator and denominator by the GCF:
\( \frac{24}{56} \) = \( \frac{\frac{24}{8}}{\frac{56}{8}} \) = \( \frac{3}{7} \)
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 or a = -7 |
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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).