| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.19 |
| Score | 0% | 64% |
The dimensions of this cylinder are height (h) = 2 and radius (r) = 6. What is the surface area?
| 80π | |
| 120π | |
| 96π | |
| 36π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(62) + 2π(6 x 2)
sa = 2π(36) + 2π(12)
sa = (2 x 36)π + (2 x 12)π
sa = 72π + 24π
sa = 96π
Simplify 9a x 9b.
| 81a2b2 | |
| 81\( \frac{a}{b} \) | |
| 18ab | |
| 81ab |
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.
9a x 9b = (9 x 9) (a x b) = 81ab
What is 9a + 3a?
| 12a | |
| 27a | |
| 12a2 | |
| 6a2 |
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.
9a + 3a = 12a
Solve 9b - 5b = -4b - 7y - 7 for b in terms of y.
| -\(\frac{2}{13}\)y - \(\frac{7}{13}\) | |
| \(\frac{5}{9}\)y + \(\frac{5}{9}\) | |
| -\(\frac{1}{11}\)y - \(\frac{7}{11}\) | |
| -2y - 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.
9b - 5y = -4b - 7y - 7
9b = -4b - 7y - 7 + 5y
9b + 4b = -7y - 7 + 5y
13b = -2y - 7
b = \( \frac{-2y - 7}{13} \)
b = \( \frac{-2y}{13} \) + \( \frac{-7}{13} \)
b = -\(\frac{2}{13}\)y - \(\frac{7}{13}\)
What is the area of a circle with a radius of 4?
| 81π | |
| 16π | |
| 4π | |
| 5π |
The formula for area is πr2:
a = πr2
a = π(42)
a = 16π