| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.64 |
| Score | 0% | 53% |
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?
| 72 m2 | |
| 8 m2 | |
| 18 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
This property states taht the order of addition or multiplication does not mater. For example, 2 + 5 and 5 + 2 are equivalent.
commutative |
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PEDMAS |
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associative |
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distributive |
The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.
What is \( 6 \)\( \sqrt{75} \) - \( 2 \)\( \sqrt{3} \)
| 12\( \sqrt{3} \) | |
| 12\( \sqrt{225} \) | |
| 4\( \sqrt{-16} \) | |
| 28\( \sqrt{3} \) |
To subtract these radicals together their radicands must be the same:
6\( \sqrt{75} \) - 2\( \sqrt{3} \)
6\( \sqrt{25 \times 3} \) - 2\( \sqrt{3} \)
6\( \sqrt{5^2 \times 3} \) - 2\( \sqrt{3} \)
(6)(5)\( \sqrt{3} \) - 2\( \sqrt{3} \)
30\( \sqrt{3} \) - 2\( \sqrt{3} \)
Now that the radicands are identical, you can subtract them:
30\( \sqrt{3} \) - 2\( \sqrt{3} \)The __________ is the smallest positive integer that is a multiple of two or more integers.
greatest common factor |
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least common multiple |
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least common factor |
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absolute value |
The least common multiple (LCM) is the smallest positive integer that is a multiple of two or more integers.
In a class of 27 students, 10 are taking German and 13 are taking Spanish. Of the students studying German or Spanish, 4 are taking both courses. How many students are not enrolled in either course?
| 15 | |
| 11 | |
| 8 | |
| 18 |
The number of students taking German or Spanish is 10 + 13 = 23. Of that group of 23, 4 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 23 - 4 = 19 who are taking at least one language. 27 - 19 = 8 students who are not taking either language.