| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.78 |
| Score | 0% | 56% |
The formula for the area of a circle is which of the following?
c = π d2 |
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c = π r2 |
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c = π d |
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c = π r |
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.
What is 5a - 8a?
| a2 | |
| -3a | |
| 40a2 | |
| -3 |
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.
5a - 8a = -3a
Which of the following statements about a triangle is not true?
sum of interior angles = 180° |
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perimeter = sum of side lengths |
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area = ½bh |
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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 BD = 18 and AD = 22, AB = ?
| 8 | |
| 6 | |
| 4 | |
| 3 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDSolve for x:
-8x + 5 > \( \frac{x}{-4} \)
| x > -\(\frac{16}{25}\) | |
| x > \(\frac{20}{31}\) | |
| x > -1\(\frac{11}{25}\) | |
| x > -1\(\frac{1}{2}\) |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.
-8x + 5 > \( \frac{x}{-4} \)
-4 x (-8x + 5) > x
(-4 x -8x) + (-4 x 5) > x
32x - 20 > x
32x - 20 - x > 0
32x - x > 20
31x > 20
x > \( \frac{20}{31} \)
x > \(\frac{20}{31}\)