| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.81 |
| Score | 0% | 56% |
Solve for c:
c2 - c - 16 = 3c + 5
| 9 or -2 | |
| 8 or 2 | |
| -3 or 7 | |
| -3 or -5 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
c2 - c - 16 = 3c + 5
c2 - c - 16 - 5 = 3c
c2 - c - 3c - 21 = 0
c2 - 4c - 21 = 0
Next, factor the quadratic equation:
c2 - 4c - 21 = 0
(c + 3)(c - 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 3) or (c - 7) must equal zero:
If (c + 3) = 0, c must equal -3
If (c - 7) = 0, c must equal 7
So the solution is that c = -3 or 7
What is the area of a circle with a radius of 4?
| 36π | |
| 81π | |
| 16π | |
| 7π |
The formula for area is πr2:
a = πr2
a = π(42)
a = 16π
If the length of AB equals the length of BD, point B __________ this line segment.
bisects |
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midpoints |
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intersects |
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trisects |
A line segment is a portion of a line with a measurable length. The midpoint of a line segment is the point exactly halfway between the endpoints. The midpoint bisects (cuts in half) the line segment.
On this circle, a line segment connecting point A to point D is called:
diameter |
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circumference |
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chord |
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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).
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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all of these statements are correct |
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you can subtract 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 |
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.