| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.60 |
| Score | 0% | 52% |
What is \( 5 \)\( \sqrt{63} \) - \( 2 \)\( \sqrt{7} \)
| 10\( \sqrt{441} \) | |
| 3\( \sqrt{7} \) | |
| 13\( \sqrt{7} \) | |
| 10\( \sqrt{63} \) |
To subtract these radicals together their radicands must be the same:
5\( \sqrt{63} \) - 2\( \sqrt{7} \)
5\( \sqrt{9 \times 7} \) - 2\( \sqrt{7} \)
5\( \sqrt{3^2 \times 7} \) - 2\( \sqrt{7} \)
(5)(3)\( \sqrt{7} \) - 2\( \sqrt{7} \)
15\( \sqrt{7} \) - 2\( \sqrt{7} \)
Now that the radicands are identical, you can subtract them:
15\( \sqrt{7} \) - 2\( \sqrt{7} \)A circular logo is enlarged to fit the lid of a jar. The new diameter is 65% larger than the original. By what percentage has the area of the logo increased?
| 37\(\frac{1}{2}\)% | |
| 20% | |
| 25% | |
| 32\(\frac{1}{2}\)% |
The area of a circle is given by the formula A = πr2 where r is the radius of the circle. The radius of a circle is its diameter divided by two so A = π(\( \frac{d}{2} \))2. If the diameter of the logo increases by 65% the radius (and, consequently, the total area) increases by \( \frac{65\text{%}}{2} \) = 32\(\frac{1}{2}\)%
Simplify \( \sqrt{8} \)
| 2\( \sqrt{2} \) | |
| 9\( \sqrt{2} \) | |
| 7\( \sqrt{2} \) | |
| 4\( \sqrt{4} \) |
To simplify a radical, factor out the perfect squares:
\( \sqrt{8} \)
\( \sqrt{4 \times 2} \)
\( \sqrt{2^2 \times 2} \)
2\( \sqrt{2} \)
If \( \left|x + 8\right| \) - 3 = 5, which of these is a possible value for x?
| 8 | |
| -8 | |
| -16 | |
| 7 |
First, solve for \( \left|x + 8\right| \):
\( \left|x + 8\right| \) - 3 = 5
\( \left|x + 8\right| \) = 5 + 3
\( \left|x + 8\right| \) = 8
The value inside the absolute value brackets can be either positive or negative so (x + 8) must equal + 8 or -8 for \( \left|x + 8\right| \) to equal 8:
| x + 8 = 8 x = 8 - 8 x = 0 | x + 8 = -8 x = -8 - 8 x = -16 |
So, x = -16 or x = 0.
Which of the following statements about exponents is false?
b1 = b |
|
all of these are false |
|
b0 = 1 |
|
b1 = 1 |
A number with an exponent (be) consists of a base (b) raised to a power (e). The exponent indicates the number of times that the base is multiplied by itself. A base with an exponent of 1 equals the base (b1 = b) and a base with an exponent of 0 equals 1 ( (b0 = 1).