| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.80 |
| Score | 0% | 56% |
Solve for a:
a + 3 = 1 - 2a
| 1 | |
| -9 | |
| -\(\frac{2}{3}\) | |
| -1\(\frac{2}{7}\) |
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.
a + 3 = 1 - 2a
a = 1 - 2a - 3
a + 2a = 1 - 3
3a = -2
a = \( \frac{-2}{3} \)
a = -\(\frac{2}{3}\)
The dimensions of this cylinder are height (h) = 4 and radius (r) = 9. What is the surface area?
| 24π | |
| 168π | |
| 140π | |
| 234π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(92) + 2π(9 x 4)
sa = 2π(81) + 2π(36)
sa = (2 x 81)π + (2 x 36)π
sa = 162π + 72π
sa = 234π
If a = 3 and x = -1, what is the value of -3a(a - x)?
| -36 | |
| 132 | |
| -49 | |
| 0 |
To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
-3a(a - x)
-3(3)(3 + 1)
-3(3)(4)
(-9)(4)
-36
Solve -3b - 5b = -5b - x - 7 for b in terms of x.
| -\(\frac{1}{8}\)x - 1\(\frac{1}{8}\) | |
| 2x - 3\(\frac{1}{2}\) | |
| 1\(\frac{3}{4}\)x - \(\frac{1}{4}\) | |
| 3x + 1\(\frac{3}{4}\) |
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.
-3b - 5x = -5b - x - 7
-3b = -5b - x - 7 + 5x
-3b + 5b = -x - 7 + 5x
2b = 4x - 7
b = \( \frac{4x - 7}{2} \)
b = \( \frac{4x}{2} \) + \( \frac{-7}{2} \)
b = 2x - 3\(\frac{1}{2}\)
What is the area of a circle with a radius of 2?
| 4π | |
| 64π | |
| 9π | |
| 49π |
The formula for area is πr2:
a = πr2
a = π(22)
a = 4π