| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
If a rectangle is twice as long as it is wide and has a perimeter of 36 meters, what is the area of the rectangle?
| 2 m2 | |
| 18 m2 | |
| 98 m2 | |
| 72 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 36 meters so the equation becomes: 2w + 2h = 36.
Putting these two equations together and solving for width (w):
2w + 2h = 36
w + h = \( \frac{36}{2} \)
w + h = 18
w = 18 - h
From the question we know that h = 2w so substituting 2w for h gives us:
w = 18 - 2w
3w = 18
w = \( \frac{18}{3} \)
w = 6
Since h = 2w that makes h = (2 x 6) = 12 and the area = h x w = 6 x 12 = 72 m2
If \( \left|b + 4\right| \) + 8 = 6, which of these is a possible value for b?
| -7 | |
| 2 | |
| -6 | |
| 9 |
First, solve for \( \left|b + 4\right| \):
\( \left|b + 4\right| \) + 8 = 6
\( \left|b + 4\right| \) = 6 - 8
\( \left|b + 4\right| \) = -2
The value inside the absolute value brackets can be either positive or negative so (b + 4) must equal - 2 or --2 for \( \left|b + 4\right| \) to equal -2:
| b + 4 = -2 b = -2 - 4 b = -6 | b + 4 = 2 b = 2 - 4 b = -2 |
So, b = -2 or b = -6.
Convert c-5 to remove the negative exponent.
| \( \frac{-1}{-5c^{5}} \) | |
| \( \frac{-1}{c^{-5}} \) | |
| \( \frac{1}{c^5} \) | |
| \( \frac{-5}{c} \) |
To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 or a = -7 |
|
a = -7 |
|
none of these is correct |
|
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).
20 members of a bridal party need transported to a wedding reception but there are only 3 5-passenger taxis available to take them. How many will need to find other transportation?
| 3 | |
| 5 | |
| 2 | |
| 7 |
There are 3 5-passenger taxis available so that's 3 x 5 = 15 total seats. There are 20 people needing transportation leaving 20 - 15 = 5 who will have to find other transportation.