| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.53 |
| Score | 0% | 71% |
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.
Which types of triangles will always have at least two sides of equal length?
equilateral and isosceles |
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equilateral and right |
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isosceles and right |
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equilateral, isosceles and right |
An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.
Simplify (5a)(2ab) - (4a2)(7b).
| 77ab2 | |
| 38ab2 | |
| -18a2b | |
| 18ab2 |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
(5a)(2ab) - (4a2)(7b)
(5 x 2)(a x a x b) - (4 x 7)(a2 x b)
(10)(a1+1 x b) - (28)(a2b)
10a2b - 28a2b
-18a2b
The formula for the area of a circle is which of the following?
a = π r |
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a = π d |
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a = π d2 |
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a = π r2 |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.
A right angle measures:
90° |
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180° |
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360° |
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45° |
A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.