| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.73 |
| Score | 0% | 55% |
If \(\left|a\right| = 7\), which of the following best describes a?
none of these is correct |
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a = 7 |
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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).
What is \( 2 \)\( \sqrt{50} \) + \( 5 \)\( \sqrt{2} \)
| 15\( \sqrt{2} \) | |
| 10\( \sqrt{2} \) | |
| 7\( \sqrt{100} \) | |
| 10\( \sqrt{100} \) |
To add these radicals together their radicands must be the same:
2\( \sqrt{50} \) + 5\( \sqrt{2} \)
2\( \sqrt{25 \times 2} \) + 5\( \sqrt{2} \)
2\( \sqrt{5^2 \times 2} \) + 5\( \sqrt{2} \)
(2)(5)\( \sqrt{2} \) + 5\( \sqrt{2} \)
10\( \sqrt{2} \) + 5\( \sqrt{2} \)
Now that the radicands are identical, you can add them together:
10\( \sqrt{2} \) + 5\( \sqrt{2} \)Which of the following statements about exponents is false?
b0 = 1 |
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b1 = b |
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all of these are false |
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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).
a(b + c) = ab + ac defines which of the following?
commutative property for division |
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distributive property for multiplication |
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distributive property for division |
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commutative property for multiplication |
The distributive property for multiplication helps in solving expressions like a(b + c). It specifies that the result of multiplying one number by the sum or difference of two numbers can be obtained by multiplying each number individually and then totaling the results: a(b + c) = ab + ac. For example, 4(10-5) = (4 x 10) - (4 x 5) = 40 - 20 = 20.
A circular logo is enlarged to fit the lid of a jar. The new diameter is 50% larger than the original. By what percentage has the area of the logo increased?
| 25% | |
| 17\(\frac{1}{2}\)% | |
| 22\(\frac{1}{2}\)% | |
| 15% |
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 50% the radius (and, consequently, the total area) increases by \( \frac{50\text{%}}{2} \) = 25%