| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.06 |
| Score | 0% | 61% |
Solve for a:
a2 - 5a - 24 = a + 3
| 2 or 1 | |
| -3 or 9 | |
| 3 or -4 | |
| 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:
a2 - 5a - 24 = a + 3
a2 - 5a - 24 - 3 = a
a2 - 5a - a - 27 = 0
a2 - 6a - 27 = 0
Next, factor the quadratic equation:
a2 - 6a - 27 = 0
(a + 3)(a - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 3) or (a - 9) must equal zero:
If (a + 3) = 0, a must equal -3
If (a - 9) = 0, a must equal 9
So the solution is that a = -3 or 9
If the area of this square is 25, what is the length of one of the diagonals?
| 5\( \sqrt{2} \) | |
| 8\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 4\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{25} \) = 5
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 52 + 52
c2 = 50
c = \( \sqrt{50} \) = \( \sqrt{25 x 2} \) = \( \sqrt{25} \) \( \sqrt{2} \)
c = 5\( \sqrt{2} \)
Solve for a:
5a - 4 > -5 + 2a
| a > \(\frac{1}{2}\) | |
| a > -\(\frac{1}{3}\) | |
| a > \(\frac{3}{4}\) | |
| a > -\(\frac{2}{3}\) |
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.
5a - 4 > -5 + 2a
5a > -5 + 2a + 4
5a - 2a > -5 + 4
3a > -1
a > \( \frac{-1}{3} \)
a > -\(\frac{1}{3}\)
A right angle measures:
360° |
|
180° |
|
45° |
|
90° |
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.
The endpoints of this line segment are at (-2, -6) and (2, 6). What is the slope of this line?
| 2\(\frac{1}{2}\) | |
| \(\frac{1}{2}\) | |
| -3 | |
| 3 |
The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, -6) and (2, 6) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(6.0) - (-6.0)}{(2) - (-2)} \) = \( \frac{12}{4} \)