| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.09 |
| Score | 0% | 62% |
If BD = 12 and AD = 21, AB = ?
| 5 | |
| 4 | |
| 10 | |
| 9 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDSolve for b:
b2 + 2b - 33 = 3b - 3
| -5 or 6 | |
| -2 or -7 | |
| 9 or -8 | |
| 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:
b2 + 2b - 33 = 3b - 3
b2 + 2b - 33 + 3 = 3b
b2 + 2b - 3b - 30 = 0
b2 - b - 30 = 0
Next, factor the quadratic equation:
b2 - b - 30 = 0
(b + 5)(b - 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b + 5) or (b - 6) must equal zero:
If (b + 5) = 0, b must equal -5
If (b - 6) = 0, b must equal 6
So the solution is that b = -5 or 6
The formula for volume of a cube in terms of height (h), length (l), and width (w) is which of the following?
2lw x 2wh + 2lh |
|
h2 x l2 x w2 |
|
lw x wh + lh |
|
h x l x w |
A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.
Solve for x:
8x - 4 = \( \frac{x}{9} \)
| \(\frac{36}{71}\) | |
| -1\(\frac{5}{31}\) | |
| 1\(\frac{9}{16}\) | |
| -1\(\frac{2}{19}\) |
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 equal sign and the answer on the other.
8x - 4 = \( \frac{x}{9} \)
9 x (8x - 4) = x
(9 x 8x) + (9 x -4) = x
72x - 36 = x
72x - 36 - x = 0
72x - x = 36
71x = 36
x = \( \frac{36}{71} \)
x = \(\frac{36}{71}\)
What is the area of a circle with a diameter of 8?
| 16π | |
| 81π | |
| 3π | |
| 4π |
The formula for area is πr2. Radius is circle \( \frac{diameter}{2} \):
r = \( \frac{d}{2} \)
r = \( \frac{8}{2} \)
r = 4
a = πr2
a = π(42)
a = 16π