| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.37 |
| Score | 0% | 67% |
Solve for x:
x2 + 13x + 11 = 4x - 3
| 5 or -8 | |
| -4 or -6 | |
| -2 or -7 | |
| 2 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 + 13x + 11 = 4x - 3
x2 + 13x + 11 + 3 = 4x
x2 + 13x - 4x + 14 = 0
x2 + 9x + 14 = 0
Next, factor the quadratic equation:
x2 + 9x + 14 = 0
(x + 2)(x + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 2) or (x + 7) must equal zero:
If (x + 2) = 0, x must equal -2
If (x + 7) = 0, x must equal -7
So the solution is that x = -2 or -7
Solve for z:
-8z + 8 = \( \frac{z}{-7} \)
| 1\(\frac{1}{55}\) | |
| -2\(\frac{1}{4}\) | |
| -1\(\frac{4}{41}\) | |
| -1\(\frac{11}{21}\) |
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 equal sign and the answer on the other.
-8z + 8 = \( \frac{z}{-7} \)
-7 x (-8z + 8) = z
(-7 x -8z) + (-7 x 8) = z
56z - 56 = z
56z - 56 - z = 0
56z - z = 56
55z = 56
z = \( \frac{56}{55} \)
z = 1\(\frac{1}{55}\)
A right angle measures:
360° |
|
180° |
|
90° |
|
45° |
A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.
What is 9a5 - 3a5?
| a510 | |
| 6a5 | |
| 27a10 | |
| 6 |
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.
9a5 - 3a5 = 6a5
If a = c = 4, b = d = 8, what is the area of this rectangle?
| 32 | |
| 9 | |
| 16 | |
| 24 |
The area of a rectangle is equal to its length x width:
a = l x w
a = a x b
a = 4 x 8
a = 32