| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.95 |
| Score | 0% | 59% |
What is the area of a circle with a diameter of 8?
| 16π | |
| 4π | |
| 3π | |
| 9π |
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
Solve 2a - 9a = 7a + 8y + 7 for a in terms of y.
| \(\frac{1}{7}\)y - 1\(\frac{1}{7}\) | |
| -3\(\frac{2}{5}\)y - 1\(\frac{2}{5}\) | |
| 14y + 6 | |
| 2\(\frac{1}{6}\)y - 1\(\frac{1}{2}\) |
To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.
2a - 9y = 7a + 8y + 7
2a = 7a + 8y + 7 + 9y
2a - 7a = 8y + 7 + 9y
-5a = 17y + 7
a = \( \frac{17y + 7}{-5} \)
a = \( \frac{17y}{-5} \) + \( \frac{7}{-5} \)
a = -3\(\frac{2}{5}\)y - 1\(\frac{2}{5}\)
Simplify (2a)(9ab) + (8a2)(3b).
| 42a2b | |
| -6ab2 | |
| 121ab2 | |
| 6a2b |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
(2a)(9ab) + (8a2)(3b)
(2 x 9)(a x a x b) + (8 x 3)(a2 x b)
(18)(a1+1 x b) + (24)(a2b)
18a2b + 24a2b
42a2b
Breaking apart a quadratic expression into a pair of binomials is called:
squaring |
|
deconstructing |
|
factoring |
|
normalizing |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
The dimensions of this cube are height (h) = 1, length (l) = 7, and width (w) = 1. What is the surface area?
| 38 | |
| 120 | |
| 30 | |
| 78 |
The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):
sa = 2lw + 2wh + 2lh
sa = (2 x 7 x 1) + (2 x 1 x 1) + (2 x 7 x 1)
sa = (14) + (2) + (14)
sa = 30