| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.39 |
| Score | 0% | 68% |
Which of the following statements about math operations is incorrect?
you can multiply monomials that have different variables and different exponents |
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all of these statements are correct |
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you can add monomials that have the same variable and the same exponent |
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you can subtract monomials that have the same variable and the same exponent |
You can only add or subtract monomials that have the same variable and the same exponent. For example, 2a + 4a = 6a and 4a2 - a2 = 3a2 but 2a + 4b and 7a - 3b cannot be combined. However, you can multiply and divide monomials with unlike terms. For example, 2a x 6b = 12ab.
The dimensions of this trapezoid are a = 5, b = 3, c = 7, d = 6, and h = 3. What is the area?
| 17\(\frac{1}{2}\) | |
| 13\(\frac{1}{2}\) | |
| 20 | |
| 22 |
The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:
a = ½(b + d)(h)
a = ½(3 + 6)(3)
a = ½(9)(3)
a = ½(27) = \( \frac{27}{2} \)
a = 13\(\frac{1}{2}\)
What is 6a8 - 2a8?
| 4 | |
| 4a8 | |
| 12a8 | |
| 12a16 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
6a8 - 2a8 = 4a8
What is the circumference of a circle with a radius of 16?
| 15π | |
| 38π | |
| 32π | |
| 7π |
The formula for circumference is circle diameter x π. Circle diameter is 2 x radius:
c = πd
c = π(2 * r)
c = π(2 * 16)
c = 32π
What is 8a5 + 9a5?
| 17a10 | |
| 17a5 | |
| -a10 | |
| 72a10 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
8a5 + 9a5 = 17a5