| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.47 |
| Score | 0% | 49% |
Solve for b:
b2 - 3b - 40 = 0
| 9 or -2 | |
| 8 or 4 | |
| -5 or 8 | |
| 9 or 4 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
b2 - 3b - 40 = 0
(b + 5)(b - 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b + 5) or (b - 8) must equal zero:
If (b + 5) = 0, b must equal -5
If (b - 8) = 0, b must equal 8
So the solution is that b = -5 or 8
The endpoints of this line segment are at (-2, -5) and (2, 7). What is the slope of this line?
| -3 | |
| 1\(\frac{1}{2}\) | |
| -2 | |
| 3 |
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, -5) and (2, 7) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(7.0) - (-5.0)}{(2) - (-2)} \) = \( \frac{12}{4} \)The dimensions of this cube are height (h) = 3, length (l) = 3, and width (w) = 3. What is the surface area?
| 160 | |
| 142 | |
| 96 | |
| 54 |
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 3 x 3) + (2 x 3 x 3) + (2 x 3 x 3)
sa = (18) + (18) + (18)
sa = 54
A cylinder with a radius (r) and a height (h) has a surface area of:
π r2h |
|
4π r2 |
|
π r2h2 |
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2(π r2) + 2π rh |
A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r2h and the surface area is 2(π r2) + 2π rh.
Which of the following is not required to define the slope-intercept equation for a line?
slope |
|
y-intercept |
|
\({\Delta y \over \Delta x}\) |
|
x-intercept |
A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.