| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.14 |
| Score | 0% | 43% |
Solve for b:
b2 + 2b + 1 = 2b + 5
| 2 or -4 | |
| 9 or -5 | |
| 2 or -2 | |
| -1 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 + 2b + 1 = 2b + 5
b2 + 2b + 1 - 5 = 2b
b2 + 2b - 2b - 4 = 0
b2 - 4 = 0
Next, factor the quadratic equation:
b2 - 4 = 0
(b - 2)(b + 2) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 2) or (b + 2) must equal zero:
If (b - 2) = 0, b must equal 2
If (b + 2) = 0, b must equal -2
So the solution is that b = 2 or -2
Solve for c:
-2c - 3 < \( \frac{c}{9} \)
| c < -\(\frac{8}{15}\) | |
| c < 2\(\frac{10}{13}\) | |
| c < 6\(\frac{6}{7}\) | |
| c < -1\(\frac{8}{19}\) |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the < sign and the answer on the other.
-2c - 3 < \( \frac{c}{9} \)
9 x (-2c - 3) < c
(9 x -2c) + (9 x -3) < c
-18c - 27 < c
-18c - 27 - c < 0
-18c - c < 27
-19c < 27
c < \( \frac{27}{-19} \)
c < -1\(\frac{8}{19}\)
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 5c + c = -c - 3y + 4 for c in terms of y.
| y + 2\(\frac{1}{4}\) | |
| -\(\frac{2}{3}\)y + \(\frac{2}{3}\) | |
| -\(\frac{1}{2}\)y - \(\frac{1}{6}\) | |
| \(\frac{9}{14}\)y - \(\frac{4}{7}\) |
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.
5c + y = -c - 3y + 4
5c = -c - 3y + 4 - y
5c + c = -3y + 4 - y
6c = -4y + 4
c = \( \frac{-4y + 4}{6} \)
c = \( \frac{-4y}{6} \) + \( \frac{4}{6} \)
c = -\(\frac{2}{3}\)y + \(\frac{2}{3}\)
Find the value of b:
8b + y = 1
-7b - 3y = 2
| \(\frac{14}{67}\) | |
| \(\frac{5}{17}\) | |
| 1 | |
| 1\(\frac{5}{11}\) |
You need to find the value of b so solve the first equation in terms of y:
8b + y = 1
y = 1 - 8b
then substitute the result (1 - 8b) into the second equation:
-7b - 3(1 - 8b) = 2
-7b + (-3 x 1) + (-3 x -8b) = 2
-7b - 3 + 24b = 2
-7b + 24b = 2 + 3
17b = 5
b = \( \frac{5}{17} \)
b = \(\frac{5}{17}\)