| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
If side x = 9cm, side y = 7cm, and side z = 15cm what is the perimeter of this triangle?
| 33cm | |
| 24cm | |
| 35cm | |
| 31cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 9cm + 7cm + 15cm = 31cm
If a = c = 1, b = d = 3, and the blue angle = 51°, what is the area of this parallelogram?
| 32 | |
| 14 | |
| 3 | |
| 15 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 1 x 3
a = 3
The dimensions of this cylinder are height (h) = 4 and radius (r) = 7. What is the surface area?
| 44π | |
| 120π | |
| 154π | |
| 8π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(72) + 2π(7 x 4)
sa = 2π(49) + 2π(28)
sa = (2 x 49)π + (2 x 28)π
sa = 98π + 56π
sa = 154π
Solve for y:
y2 + 2y - 39 = -y + 1
| 4 or -3 | |
| 4 or -2 | |
| 7 or -8 | |
| 5 or -8 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
y2 + 2y - 39 = -y + 1
y2 + 2y - 39 - 1 = -y
y2 + 2y + y - 40 = 0
y2 + 3y - 40 = 0
Next, factor the quadratic equation:
y2 + 3y - 40 = 0
(y - 5)(y + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y - 5) or (y + 8) must equal zero:
If (y - 5) = 0, y must equal 5
If (y + 8) = 0, y must equal -8
So the solution is that y = 5 or -8
Which of the following statements about math operations is incorrect?
you can add monomials that have the same variable and the same exponent |
|
you can subtract monomials that have the same variable and the same exponent |
|
you can multiply monomials that have different variables and different exponents |
|
all of these statements are correct |
You can only add or subtract monomials that have the same variable and the same exponent. For example, 2a + 4a = 6a and 4a2 - a2 = 3a2 but 2a + 4b and 7a - 3b cannot be combined. However, you can multiply and divide monomials with unlike terms. For example, 2a x 6b = 12ab.