| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.18 |
| Score | 0% | 64% |
Which of the following statements about math operations is incorrect?
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 multiply monomials that have different variables and different exponents |
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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 = 4, b = 5, c = 5, d = 9, and h = 2. What is the area?
| 15 | |
| 16 | |
| 14 | |
| 27\(\frac{1}{2}\) |
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(5 + 9)(2)
a = ½(14)(2)
a = ½(28) = \( \frac{28}{2} \)
a = 14
On this circle, line segment AB is the:
circumference |
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chord |
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diameter |
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radius |
A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).
What is 9a + 3a?
| a2 | |
| 12a | |
| 27a2 | |
| 27a |
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.
9a + 3a = 12a
The endpoints of this line segment are at (-2, 1) and (2, -5). What is the slope of this line?
| -1\(\frac{1}{2}\) | |
| -\(\frac{1}{2}\) | |
| 1 | |
| 1\(\frac{1}{2}\) |
The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, 1) and (2, -5) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-5.0) - (1.0)}{(2) - (-2)} \) = \( \frac{-6}{4} \)