| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.77 |
| Score | 0% | 55% |
Solve -2c - 5c = 9c + 3z - 1 for c in terms of z.
| \(\frac{3}{7}\)z + \(\frac{1}{7}\) | |
| \(\frac{5}{9}\)z - \(\frac{4}{9}\) | |
| -\(\frac{8}{11}\)z + \(\frac{1}{11}\) | |
| -7z - 3 |
To solve this equation, isolate the variable for which you are solving (c) on one side of the equation and put everything else on the other side.
-2c - 5z = 9c + 3z - 1
-2c = 9c + 3z - 1 + 5z
-2c - 9c = 3z - 1 + 5z
-11c = 8z - 1
c = \( \frac{8z - 1}{-11} \)
c = \( \frac{8z}{-11} \) + \( \frac{-1}{-11} \)
c = -\(\frac{8}{11}\)z + \(\frac{1}{11}\)
Breaking apart a quadratic expression into a pair of binomials is called:
factoring |
|
squaring |
|
deconstructing |
|
normalizing |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
For this diagram, the Pythagorean theorem states that b2 = ?
c2 - a2 |
|
c2 + a2 |
|
a2 - c2 |
|
c - a |
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, \(c = \sqrt{a + b}\)
Solve for b:
b2 + 9b + 32 = -2b + 2
| -5 or -6 | |
| -1 or -2 | |
| 2 or -9 | |
| -3 or -5 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
b2 + 9b + 32 = -2b + 2
b2 + 9b + 32 - 2 = -2b
b2 + 9b + 2b + 30 = 0
b2 + 11b + 30 = 0
Next, factor the quadratic equation:
b2 + 11b + 30 = 0
(b + 5)(b + 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b + 5) or (b + 6) must equal zero:
If (b + 5) = 0, b must equal -5
If (b + 6) = 0, b must equal -6
So the solution is that b = -5 or -6
If angle a = 51° and angle b = 38° what is the length of angle c?
| 92° | |
| 81° | |
| 82° | |
| 91° |
The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 51° - 38° = 91°