| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.17 |
| Score | 0% | 63% |
The endpoints of this line segment are at (-2, -4) and (2, 4). What is the slope-intercept equation for this line?
| y = 3x - 4 | |
| y = x - 2 | |
| y = 2x + 0 | |
| y = \(\frac{1}{2}\)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 0. 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, 4) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(4.0) - (-4.0)}{(2) - (-2)} \) = \( \frac{8}{4} \)Plugging these values into the slope-intercept equation:
y = 2x + 0
If angle a = 46° and angle b = 65° what is the length of angle d?
| 138° | |
| 134° | |
| 125° | |
| 136° |
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° - 65° = 69°
So, d° = 65° + 69° = 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°
If angle a = 67° and angle b = 21° what is the length of angle c?
| 92° | |
| 71° | |
| 112° | |
| 49° |
The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 67° - 21° = 92°
What is 6a7 - 5a7?
| 30a14 | |
| 11a14 | |
| 1a7 | |
| 30a7 |
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.
6a7 - 5a7 = 1a7
If BD = 14 and AD = 24, AB = ?
| 17 | |
| 8 | |
| 10 | |
| 16 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BD