| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
Solve for z:
z2 - 2z - 14 = 2z - 2
| 3 or 3 | |
| -2 or 6 | |
| 9 or 6 | |
| 6 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 - 2z - 14 = 2z - 2
z2 - 2z - 14 + 2 = 2z
z2 - 2z - 2z - 12 = 0
z2 - 4z - 12 = 0
Next, factor the quadratic equation:
z2 - 4z - 12 = 0
(z + 2)(z - 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z + 2) or (z - 6) must equal zero:
If (z + 2) = 0, z must equal -2
If (z - 6) = 0, z must equal 6
So the solution is that z = -2 or 6
The dimensions of this cylinder are height (h) = 8 and radius (r) = 3. What is the volume?
| 72π | |
| 32π | |
| 12π | |
| 125π |
The volume of a cylinder is πr2h:
v = πr2h
v = π(32 x 8)
v = 72π
If a = 7, b = 6, c = 2, and d = 9, what is the perimeter of this quadrilateral?
| 28 | |
| 18 | |
| 24 | |
| 20 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 7 + 6 + 2 + 9
p = 24
Factor y2 + y - 72
| (y + 8)(y + 9) | |
| (y + 8)(y - 9) | |
| (y - 8)(y - 9) | |
| (y - 8)(y + 9) |
To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -72 as well and sum (Inside, Outside) to equal 1. For this problem, those two numbers are -8 and 9. Then, plug these into a set of binomials using the square root of the First variable (y2):
y2 + y - 72
y2 + (-8 + 9)y + (-8 x 9)
(y - 8)(y + 9)
On this circle, line segment AB is the:
diameter |
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radius |
|
circumference |
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chord |
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).