| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.56 |
| Score | 0% | 71% |
If \(\left|a\right| = 7\), which of the following best describes a?
a = 7 |
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a = 7 or a = -7 |
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a = -7 |
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none of these is correct |
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).
How many hours does it take a car to travel 455 miles at an average speed of 65 miles per hour?
| 7 hours | |
| 6 hours | |
| 8 hours | |
| 9 hours |
Average speed in miles per hour is the number of miles traveled divided by the number of hours:
speed = \( \frac{\text{distance}}{\text{time}} \)Solving for time:
time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{455mi}{65mph} \)
7 hours
Which of the following statements about exponents is false?
b1 = 1 |
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b1 = b |
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all of these are false |
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b0 = 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).
Which of the following is a mixed number?
\({5 \over 7} \) |
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\(1 {2 \over 5} \) |
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\({7 \over 5} \) |
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\({a \over 5} \) |
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.
Simplify \( \frac{20}{52} \).
| \( \frac{9}{20} \) | |
| \( \frac{7}{12} \) | |
| \( \frac{5}{13} \) | |
| \( \frac{1}{2} \) |
To simplify this fraction, first find the greatest common factor between them. The factors of 20 are [1, 2, 4, 5, 10, 20] and the factors of 52 are [1, 2, 4, 13, 26, 52]. They share 3 factors [1, 2, 4] making 4 their greatest common factor (GCF).
Next, divide both numerator and denominator by the GCF:
\( \frac{20}{52} \) = \( \frac{\frac{20}{4}}{\frac{52}{4}} \) = \( \frac{5}{13} \)