| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.88 |
| Score | 0% | 58% |
If BD = 8 and AD = 15, AB = ?
| 7 | |
| 19 | |
| 5 | |
| 11 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDSolve for b:
b2 + 13b + 40 = 0
| 5 or -2 | |
| 4 or 1 | |
| -5 or -8 | |
| 9 or -1 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
b2 + 13b + 40 = 0
(b + 5)(b + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b + 5) or (b + 8) must equal zero:
If (b + 5) = 0, b must equal -5
If (b + 8) = 0, b must equal -8
So the solution is that b = -5 or -8
Which of the following is not required to define the slope-intercept equation for a line?
\({\Delta y \over \Delta x}\) |
|
slope |
|
x-intercept |
|
y-intercept |
A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.
If angle a = 22° and angle b = 36° what is the length of angle c?
| 122° | |
| 77° | |
| 79° | |
| 93° |
The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 22° - 36° = 122°
Find the value of b:
-7b + x = 5
-7b - 4x = -7
| -1\(\frac{4}{7}\) | |
| -2\(\frac{1}{6}\) | |
| 4\(\frac{2}{5}\) | |
| -\(\frac{13}{35}\) |
You need to find the value of b so solve the first equation in terms of x:
-7b + x = 5
x = 5 + 7b
then substitute the result (5 - -7b) into the second equation:
-7b - 4(5 + 7b) = -7
-7b + (-4 x 5) + (-4 x 7b) = -7
-7b - 20 - 28b = -7
-7b - 28b = -7 + 20
-35b = 13
b = \( \frac{13}{-35} \)
b = -\(\frac{13}{35}\)