| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.71 |
| Score | 0% | 74% |
Which of the following statements about math operations is incorrect?
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 |
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all of these statements are correct |
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you can multiply monomials that have different variables and different exponents |
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.
What is the circumference of a circle with a radius of 19?
| 12π | |
| 36π | |
| 38π | |
| 4π |
The formula for circumference is circle diameter x π. Circle diameter is 2 x radius:
c = πd
c = π(2 * r)
c = π(2 * 19)
c = 38π
Which of the following statements about a triangle is not true?
area = ½bh |
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sum of interior angles = 180° |
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perimeter = sum of side lengths |
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exterior angle = sum of two adjacent interior angles |
A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.
If side x = 8cm, side y = 14cm, and side z = 12cm what is the perimeter of this triangle?
| 22cm | |
| 26cm | |
| 27cm | |
| 34cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 8cm + 14cm + 12cm = 34cm
Simplify 4a x 3b.
| 12ab | |
| 12\( \frac{b}{a} \) | |
| 12\( \frac{a}{b} \) | |
| 12a2b2 |
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.
4a x 3b = (4 x 3) (a x b) = 12ab