| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
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?
| 72 m2 | |
| 8 m2 | |
| 32 m2 | |
| 128 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
\({b + c \over a} = {b \over a} + {c \over a}\) 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 the following is an improper fraction?
\({a \over 5} \) |
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\({2 \over 5} \) |
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\(1 {2 \over 5} \) |
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\({7 \over 5} \) |
A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.
What is \( \frac{4}{5} \) ÷ \( \frac{1}{9} \)?
| \(\frac{1}{12}\) | |
| \(\frac{1}{20}\) | |
| 7\(\frac{1}{5}\) | |
| \(\frac{1}{28}\) |
To divide fractions, invert the second fraction and then multiply:
\( \frac{4}{5} \) ÷ \( \frac{1}{9} \) = \( \frac{4}{5} \) x \( \frac{9}{1} \)
To multiply fractions, multiply the numerators together and then multiply the denominators together:
\( \frac{4}{5} \) x \( \frac{9}{1} \) = \( \frac{4 x 9}{5 x 1} \) = \( \frac{36}{5} \) = 7\(\frac{1}{5}\)
If \( \left|b + 2\right| \) - 2 = -3, which of these is a possible value for b?
| 14 | |
| -6 | |
| -18 | |
| -1 |
First, solve for \( \left|b + 2\right| \):
\( \left|b + 2\right| \) - 2 = -3
\( \left|b + 2\right| \) = -3 + 2
\( \left|b + 2\right| \) = -1
The value inside the absolute value brackets can be either positive or negative so (b + 2) must equal - 1 or --1 for \( \left|b + 2\right| \) to equal -1:
| b + 2 = -1 b = -1 - 2 b = -3 | b + 2 = 1 b = 1 - 2 b = -1 |
So, b = -1 or b = -3.