| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.26 |
| Score | 0% | 65% |
What is the circumference of a circle with a diameter of 14?
| 12π | |
| 14π | |
| 9π | |
| 13π |
The formula for circumference is circle diameter x π:
c = πd
c = 14π
A coordinate grid is composed of which of the following?
all of these |
|
origin |
|
y-axis |
|
x-axis |
The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.
Breaking apart a quadratic expression into a pair of binomials is called:
deconstructing |
|
factoring |
|
normalizing |
|
squaring |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
Solve 3b + 5b = -3b - 7y - 4 for b in terms of y.
| -4y + 8 | |
| \(\frac{2}{3}\)y - \(\frac{3}{4}\) | |
| -2y - \(\frac{2}{3}\) | |
| -9y + 1 |
To solve this equation, isolate the variable for which you are solving (b) on one side of the equation and put everything else on the other side.
3b + 5y = -3b - 7y - 4
3b = -3b - 7y - 4 - 5y
3b + 3b = -7y - 4 - 5y
6b = -12y - 4
b = \( \frac{-12y - 4}{6} \)
b = \( \frac{-12y}{6} \) + \( \frac{-4}{6} \)
b = -2y - \(\frac{2}{3}\)
Solve for c:
c2 + 5c + 12 = -5c - 4
| 5 or -9 | |
| 8 or -9 | |
| -2 or -5 | |
| -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:
c2 + 5c + 12 = -5c - 4
c2 + 5c + 12 + 4 = -5c
c2 + 5c + 5c + 16 = 0
c2 + 10c + 16 = 0
Next, factor the quadratic equation:
c2 + 10c + 16 = 0
(c + 2)(c + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 2) or (c + 8) must equal zero:
If (c + 2) = 0, c must equal -2
If (c + 8) = 0, c must equal -8
So the solution is that c = -2 or -8