| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
Solve for z:
z2 + 5z - 12 = -z + 4
| 2 or -8 | |
| 3 or -8 | |
| 3 or -9 | |
| 8 or -6 |
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 + 5z - 12 = -z + 4
z2 + 5z - 12 - 4 = -z
z2 + 5z + z - 16 = 0
z2 + 6z - 16 = 0
Next, factor the quadratic equation:
z2 + 6z - 16 = 0
(z - 2)(z + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 2) or (z + 8) must equal zero:
If (z - 2) = 0, z must equal 2
If (z + 8) = 0, z must equal -8
So the solution is that z = 2 or -8
The dimensions of this cube are height (h) = 1, length (l) = 4, and width (w) = 8. What is the surface area?
| 40 | |
| 88 | |
| 66 | |
| 254 |
The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):
sa = 2lw + 2wh + 2lh
sa = (2 x 4 x 8) + (2 x 8 x 1) + (2 x 4 x 1)
sa = (64) + (16) + (8)
sa = 88
The endpoints of this line segment are at (-2, 4) and (2, -2). What is the slope-intercept equation for this line?
| y = 2x + 4 | |
| y = -1\(\frac{1}{2}\)x + 1 | |
| y = 1\(\frac{1}{2}\)x - 1 | |
| y = -x + 4 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is 1. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, 4) and (2, -2) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-2.0) - (4.0)}{(2) - (-2)} \) = \( \frac{-6}{4} \)Plugging these values into the slope-intercept equation:
y = -1\(\frac{1}{2}\)x + 1
A coordinate grid is composed of which of the following?
x-axis |
|
all of these |
|
y-axis |
|
origin |
The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
supplementary, vertical |
|
obtuse, acute |
|
vertical, supplementary |
|
acute, obtuse |
Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).