| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.73 |
| Score | 0% | 55% |
The endpoints of this line segment are at (-2, -6) and (2, 4). What is the slope-intercept equation for this line?
| y = -2x - 3 | |
| y = 3x + 4 | |
| y = -2\(\frac{1}{2}\)x - 2 | |
| y = 2\(\frac{1}{2}\)x - 1 |
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, -6) and (2, 4) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(4.0) - (-6.0)}{(2) - (-2)} \) = \( \frac{10}{4} \)Plugging these values into the slope-intercept equation:
y = 2\(\frac{1}{2}\)x - 1
The formula for the area of a circle is which of the following?
c = π d |
|
c = π r2 |
|
c = π d2 |
|
c = π r |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.
If BD = 13 and AD = 19, AB = ?
| 2 | |
| 6 | |
| 13 | |
| 9 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDSimplify (9a)(4ab) + (2a2)(9b).
| 54a2b | |
| 143ab2 | |
| 54ab2 | |
| 18a2b |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
(9a)(4ab) + (2a2)(9b)
(9 x 4)(a x a x b) + (2 x 9)(a2 x b)
(36)(a1+1 x b) + (18)(a2b)
36a2b + 18a2b
54a2b
If the area of this square is 36, what is the length of one of the diagonals?
| 9\( \sqrt{2} \) | |
| 8\( \sqrt{2} \) | |
| 7\( \sqrt{2} \) | |
| 6\( \sqrt{2} \) |
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 = \( \sqrt{a} \) = \( \sqrt{36} \) = 6
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 = 62 + 62
c2 = 72
c = \( \sqrt{72} \) = \( \sqrt{36 x 2} \) = \( \sqrt{36} \) \( \sqrt{2} \)
c = 6\( \sqrt{2} \)