| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.88 |
| Score | 0% | 58% |
A cylinder with a radius (r) and a height (h) has a surface area of:
π r2h2 |
|
π r2h |
|
4π r2 |
|
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.
What is 4a5 + 8a5?
| 12a5 | |
| 12a10 | |
| -4 | |
| 12 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
4a5 + 8a5 = 12a5
Solve for y:
-4y - 1 = \( \frac{y}{-9} \)
| -1\(\frac{13}{36}\) | |
| 10 | |
| \(\frac{40}{41}\) | |
| -\(\frac{9}{35}\) |
To solve this equation, 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.
-4y - 1 = \( \frac{y}{-9} \)
-9 x (-4y - 1) = y
(-9 x -4y) + (-9 x -1) = y
36y + 9 = y
36y + 9 - y = 0
36y - y = -9
35y = -9
y = \( \frac{-9}{35} \)
y = -\(\frac{9}{35}\)
The endpoints of this line segment are at (-2, -4) and (2, 6). What is the slope-intercept equation for this line?
| y = 2\(\frac{1}{2}\)x + 1 | |
| y = -3x - 3 | |
| y = 2\(\frac{1}{2}\)x - 3 | |
| y = x + 0 |
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, 6) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(6.0) - (-4.0)}{(2) - (-2)} \) = \( \frac{10}{4} \)Plugging these values into the slope-intercept equation:
y = 2\(\frac{1}{2}\)x + 1
What is the area of a circle with a diameter of 8?
| 8π | |
| 7π | |
| 81π | |
| 16π |
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