| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
The dimensions of this cylinder are height (h) = 4 and radius (r) = 7. What is the surface area?
| 154π | |
| 60π | |
| 66π | |
| 72π |
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 c:
c2 + 3c - 67 = 5c - 4
| -4 or -7 | |
| -7 or 9 | |
| 9 or 6 | |
| 8 or 4 |
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:
c2 + 3c - 67 = 5c - 4
c2 + 3c - 67 + 4 = 5c
c2 + 3c - 5c - 63 = 0
c2 - 2c - 63 = 0
Next, factor the quadratic equation:
c2 - 2c - 63 = 0
(c + 7)(c - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 7) or (c - 9) must equal zero:
If (c + 7) = 0, c must equal -7
If (c - 9) = 0, c must equal 9
So the solution is that c = -7 or 9
Which of the following statements about a triangle is not true?
exterior angle = sum of two adjacent interior angles |
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area = ½bh |
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perimeter = sum of side lengths |
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sum of interior angles = 180° |
A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.
Which of the following statements about math operations is incorrect?
you can multiply monomials that have different variables and different exponents |
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you can add monomials that have the same variable and the same exponent |
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you can subtract monomials that have the same variable and the same exponent |
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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.
If a = c = 8, b = d = 7, and the blue angle = 71°, what is the area of this parallelogram?
| 36 | |
| 35 | |
| 20 | |
| 56 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 8 x 7
a = 56