| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
The dimensions of this cylinder are height (h) = 9 and radius (r) = 1. What is the surface area?
| 120π | |
| 20π | |
| 40π | |
| 100π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(12) + 2π(1 x 9)
sa = 2π(1) + 2π(9)
sa = (2 x 1)π + (2 x 9)π
sa = 2π + 18π
sa = 20π
Simplify (9a)(4ab) - (3a2)(9b).
| 63a2b | |
| -9ab2 | |
| 156ab2 | |
| 9a2b |
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)(4ab) - (3a2)(9b)
(9 x 4)(a x a x b) - (3 x 9)(a2 x b)
(36)(a1+1 x b) - (27)(a2b)
36a2b - 27a2b
9a2b
What is 3a9 - 7a9?
| -4 | |
| 21a9 | |
| a918 | |
| -4a9 |
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.
3a9 - 7a9 = -4a9
If a = 4, b = 8, c = 2, and d = 3, what is the perimeter of this quadrilateral?
| 22 | |
| 17 | |
| 19 | |
| 15 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 4 + 8 + 2 + 3
p = 17
Solve -a - 2a = a - 3y - 4 for a in terms of y.
| 4\(\frac{1}{2}\)y - 4 | |
| 1\(\frac{3}{7}\)y + \(\frac{4}{7}\) | |
| \(\frac{1}{2}\)y + 2 | |
| -\(\frac{7}{12}\)y + \(\frac{1}{3}\) |
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.
-a - 2y = a - 3y - 4
-a = a - 3y - 4 + 2y
-a - a = -3y - 4 + 2y
-2a = -y - 4
a = \( \frac{-y - 4}{-2} \)
a = \( \frac{-y}{-2} \) + \( \frac{-4}{-2} \)
a = \(\frac{1}{2}\)y + 2