| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
Solve for c:
c2 - 3c - 33 = -3c + 3
| 7 or -8 | |
| 5 or -7 | |
| 6 or -6 | |
| 6 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:
c2 - 3c - 33 = -3c + 3
c2 - 3c - 33 - 3 = -3c
c2 - 3c + 3c - 36 = 0
c2 - 36 = 0
Next, factor the quadratic equation:
c2 - 36 = 0
(c - 6)(c + 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c - 6) or (c + 6) must equal zero:
If (c - 6) = 0, c must equal 6
If (c + 6) = 0, c must equal -6
So the solution is that c = 6 or -6
What is the circumference of a circle with a diameter of 14?
| 38π | |
| 24π | |
| 26π | |
| 14π |
The formula for circumference is circle diameter x π:
c = πd
c = 14π
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
vertical, supplementary |
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obtuse, acute |
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supplementary, vertical |
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acute, obtuse |
Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).
Which of the following statements about math operations is incorrect?
all of these statements are correct |
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you can subtract monomials that have the same variable and the same exponent |
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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 |
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 b = 8 and x = -9, what is the value of 4b(b - x)?
| 0 | |
| 16 | |
| 32 | |
| 544 |
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.)
4b(b - x)
4(8)(8 + 9)
4(8)(17)
(32)(17)
544