| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.00 |
| Score | 0% | 60% |
The endpoints of this line segment are at (-2, 5) and (2, -3). What is the slope-intercept equation for this line?
| y = 2\(\frac{1}{2}\)x + 3 | |
| y = -2x + 1 | |
| y = 2x + 4 | |
| 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, 5) and (2, -3) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-3.0) - (5.0)}{(2) - (-2)} \) = \( \frac{-8}{4} \)Plugging these values into the slope-intercept equation:
y = -2x + 1
For this diagram, the Pythagorean theorem states that b2 = ?
c - a |
|
c2 - a2 |
|
c2 + a2 |
|
a2 - c2 |
The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c2) is equal to the sum of the two perpendicular sides squared (a2 + b2): c2 = a2 + b2 or, solved for c, \(c = \sqrt{a + b}\)
Simplify 9a x 8b.
| 17ab | |
| 72\( \frac{b}{a} \) | |
| 72\( \frac{a}{b} \) | |
| 72ab |
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 x 8b = (9 x 8) (a x b) = 72ab
If angle a = 46° and angle b = 51° what is the length of angle d?
| 153° | |
| 144° | |
| 134° | |
| 141° |
An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:
d° = b° + c°
To find angle c, remember that the sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 46° - 51° = 83°
So, d° = 51° + 83° = 134°
A shortcut to get this answer is to remember that angles around a line add up to 180°:
a° + d° = 180°
d° = 180° - a°
d° = 180° - 46° = 134°
What is the area of a circle with a diameter of 10?
| 7π | |
| 9π | |
| 36π | |
| 25π |
The formula for area is πr2. Radius is circle \( \frac{diameter}{2} \):
r = \( \frac{d}{2} \)
r = \( \frac{10}{2} \)
r = 5
a = πr2
a = π(52)
a = 25π