| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.56 |
| Score | 0% | 71% |
What is the area of a circle with a diameter of 8?
| 16π | |
| 7π | |
| 49π | |
| 6π |
The formula for area is πr2. Radius is circle \( \frac{diameter}{2} \):
r = \( \frac{d}{2} \)
r = \( \frac{8}{2} \)
r = 4
a = πr2
a = π(42)
a = 16π
A(n) __________ is two expressions separated by an equal sign.
formula |
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expression |
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equation |
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problem |
An equation is two expressions separated by an equal sign. The key to solving equations is to repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.
The formula for volume of a cube in terms of height (h), length (l), and width (w) is which of the following?
h2 x l2 x w2 |
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h x l x w |
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lw x wh + lh |
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2lw x 2wh + 2lh |
A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.
A right angle measures:
90° |
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180° |
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45° |
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360° |
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.
Solve for z:
z2 - 14z + 47 = -z + 5
| 6 or 7 | |
| 5 or 1 | |
| -8 or -8 | |
| 8 or -2 |
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:
z2 - 14z + 47 = -z + 5
z2 - 14z + 47 - 5 = -z
z2 - 14z + z + 42 = 0
z2 - 13z + 42 = 0
Next, factor the quadratic equation:
z2 - 13z + 42 = 0
(z - 6)(z - 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 6) or (z - 7) must equal zero:
If (z - 6) = 0, z must equal 6
If (z - 7) = 0, z must equal 7
So the solution is that z = 6 or 7