| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.80 |
| Score | 0% | 56% |
Solve for c:
2c + 8 = \( \frac{c}{-3} \)
| 1\(\frac{1}{9}\) | |
| 1\(\frac{5}{7}\) | |
| -1\(\frac{5}{9}\) | |
| -3\(\frac{3}{7}\) |
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.
2c + 8 = \( \frac{c}{-3} \)
-3 x (2c + 8) = c
(-3 x 2c) + (-3 x 8) = c
-6c - 24 = c
-6c - 24 - c = 0
-6c - c = 24
-7c = 24
c = \( \frac{24}{-7} \)
c = -3\(\frac{3}{7}\)
Solve for y:
y2 - 8y - 9 = 0
| 3 or -5 | |
| 7 or 1 | |
| 7 or -1 | |
| -1 or 9 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
y2 - 8y - 9 = 0
(y + 1)(y - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 1) or (y - 9) must equal zero:
If (y + 1) = 0, y must equal -1
If (y - 9) = 0, y must equal 9
So the solution is that y = -1 or 9
Which types of triangles will always have at least two sides of equal length?
equilateral, isosceles and right |
|
isosceles and right |
|
equilateral and isosceles |
|
equilateral and right |
An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.
The dimensions of this cylinder are height (h) = 2 and radius (r) = 6. What is the surface area?
| 120π | |
| 272π | |
| 96π | |
| 70π |
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
What is the circumference of a circle with a radius of 16?
| 32π | |
| 38π | |
| 20π | |
| 19π |
The formula for circumference is circle diameter x π. Circle diameter is 2 x radius:
c = πd
c = π(2 * r)
c = π(2 * 16)
c = 32π