| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.74 |
| Score | 0% | 55% |
The endpoints of this line segment are at (-2, 0) and (2, 4). What is the slope-intercept equation for this line?
| y = 3x + 1 | |
| y = x + 2 | |
| y = x + 4 | |
| y = 2\(\frac{1}{2}\)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 2. 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, 0) and (2, 4) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(4.0) - (0.0)}{(2) - (-2)} \) = \( \frac{4}{4} \)Plugging these values into the slope-intercept equation:
y = x + 2
For this diagram, the Pythagorean theorem states that b2 = ?
a2 - c2 |
|
c - a |
|
c2 + a2 |
|
c2 - a2 |
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, \(c = \sqrt{a + b}\)
If BD = 17 and AD = 18, AB = ?
| 1 | |
| 8 | |
| 18 | |
| 14 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDSolve for y:
y2 - 3y - 40 = 0
| 8 or -4 | |
| -4 or -7 | |
| -5 or 8 | |
| -2 or -3 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
y2 - 3y - 40 = 0
(y + 5)(y - 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 5) or (y - 8) must equal zero:
If (y + 5) = 0, y must equal -5
If (y - 8) = 0, y must equal 8
So the solution is that y = -5 or 8
The dimensions of this trapezoid are a = 6, b = 4, c = 8, d = 7, and h = 5. What is the area?
| 13\(\frac{1}{2}\) | |
| 16 | |
| 27\(\frac{1}{2}\) | |
| 10 |
The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:
a = ½(b + d)(h)
a = ½(4 + 7)(5)
a = ½(11)(5)
a = ½(55) = \( \frac{55}{2} \)
a = 27\(\frac{1}{2}\)