| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.60 |
| Score | 0% | 72% |
What is \( \frac{5}{2} \) + \( \frac{6}{4} \)?
| 4 | |
| 2 \( \frac{6}{15} \) | |
| 2 \( \frac{1}{4} \) | |
| 2 \( \frac{2}{10} \) |
To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 2 are [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] and the first few multiples of 4 are [4, 8, 12, 16, 20, 24, 28, 32, 36, 40]. The first few multiples they share are [4, 8, 12, 16, 20] making 4 the smallest multiple 2 and 4 share.
Next, convert the fractions so each denominator equals the lowest common multiple:
\( \frac{5 x 2}{2 x 2} \) + \( \frac{6 x 1}{4 x 1} \)
\( \frac{10}{4} \) + \( \frac{6}{4} \)
Now, because the fractions share a common denominator, you can add them:
\( \frac{10 + 6}{4} \) = \( \frac{16}{4} \) = 4
What is b4 + 5b4?
| 6b-8 | |
| 6b16 | |
| 6b4 | |
| -4b-4 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:
1b4 + 5b4
(1 + 5)b4
6b4
What is (z5)2?
| z7 | |
| z10 | |
| z-3 | |
| 2z5 |
To raise a term with an exponent to another exponent, retain the base and multiply the exponents:
(z5)2What is -5a6 - 9a6?
| -14a6 | |
| 14a6 | |
| 4a-12 | |
| 4a36 |
To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so subtract the coefficients and retain the base and exponent:
-5a6 - 9a6
(-5 - 9)a6
-14a6
What is the distance in miles of a trip that takes 9 hours at an average speed of 65 miles per hour?
| 20 miles | |
| 15 miles | |
| 180 miles | |
| 585 miles |
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 distance:
distance = \( \text{speed} \times \text{time} \)
distance = \( 65mph \times 9h \)
585 miles