| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
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A cylinder with a radius (r) and a height (h) has a surface area of:
π r2h2 |
|
4π r2 |
|
π r2h |
|
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.
Solve for b:
3b - 9 > \( \frac{b}{9} \)
| b > 3\(\frac{3}{5}\) | |
| b > 3\(\frac{3}{26}\) | |
| b > -\(\frac{20}{29}\) | |
| b > -\(\frac{8}{9}\) |
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 > sign and the answer on the other.
3b - 9 > \( \frac{b}{9} \)
9 x (3b - 9) > b
(9 x 3b) + (9 x -9) > b
27b - 81 > b
27b - 81 - b > 0
27b - b > 81
26b > 81
b > \( \frac{81}{26} \)
b > 3\(\frac{3}{26}\)
The endpoints of this line segment are at (-2, -2) and (2, -4). What is the slope-intercept equation for this line?
| y = 2x - 4 | |
| y = -2\(\frac{1}{2}\)x + 3 | |
| y = x - 2 | |
| y = -\(\frac{1}{2}\)x - 3 |
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 -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, -2) and (2, -4) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-4.0) - (-2.0)}{(2) - (-2)} \) = \( \frac{-2}{4} \)Plugging these values into the slope-intercept equation:
y = -\(\frac{1}{2}\)x - 3
What is 9a9 + 9a9?
| 0 | |
| 81a18 | |
| 18a9 | |
| 18a18 |
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.
9a9 + 9a9 = 18a9
If the area of this square is 49, what is the length of one of the diagonals?
| \( \sqrt{2} \) | |
| 5\( \sqrt{2} \) | |
| 3\( \sqrt{2} \) | |
| 7\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{49} \) = 7
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 72 + 72
c2 = 98
c = \( \sqrt{98} \) = \( \sqrt{49 x 2} \) = \( \sqrt{49} \) \( \sqrt{2} \)
c = 7\( \sqrt{2} \)