| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.40 |
| Score | 0% | 68% |
Solve for z:
z2 - 4z - 21 = 0
| 4 or -7 | |
| 9 or -4 | |
| -6 or -9 | |
| -3 or 7 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
z2 - 4z - 21 = 0
(z + 3)(z - 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z + 3) or (z - 7) must equal zero:
If (z + 3) = 0, z must equal -3
If (z - 7) = 0, z must equal 7
So the solution is that z = -3 or 7
Solve for x:
x2 + 11x + 8 = 4x - 4
| 8 or -8 | |
| -3 or -4 | |
| 6 or -2 | |
| -7 or -8 |
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:
x2 + 11x + 8 = 4x - 4
x2 + 11x + 8 + 4 = 4x
x2 + 11x - 4x + 12 = 0
x2 + 7x + 12 = 0
Next, factor the quadratic equation:
x2 + 7x + 12 = 0
(x + 3)(x + 4) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 3) or (x + 4) must equal zero:
If (x + 3) = 0, x must equal -3
If (x + 4) = 0, x must equal -4
So the solution is that x = -3 or -4
What is 2a - 3a?
| -1 | |
| 6a | |
| 5a2 | |
| -1a |
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.
2a - 3a = -1a
What is 5a + 9a?
| -4a2 | |
| a2 | |
| 14a | |
| 45a2 |
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.
5a + 9a = 14a
A trapezoid is a quadrilateral with one set of __________ sides.
parallel |
|
equal length |
|
right angle |
|
equal angle |
A trapezoid is a quadrilateral with one set of parallel sides.