| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.27 |
| Score | 0% | 65% |
Solve for c:
c2 - 7c + 12 = 0
| 8 or -9 | |
| 2 or -3 | |
| 8 or -2 | |
| 3 or 4 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
c2 - 7c + 12 = 0
(c - 3)(c - 4) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c - 3) or (c - 4) must equal zero:
If (c - 3) = 0, c must equal 3
If (c - 4) = 0, c must equal 4
So the solution is that c = 3 or 4
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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acute, obtuse |
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obtuse, acute |
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supplementary, vertical |
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).
If a = 8 and y = 8, what is the value of a(a - y)?
| 20 | |
| 0 | |
| -70 | |
| 64 |
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.)
a(a - y)
1(8)(8 - 8)
1(8)(0)
(8)(0)
0
Solve for b:
b2 + b - 2 = -4b + 4
| 2 or -3 | |
| 8 or 1 | |
| 1 or -6 | |
| -2 or -5 |
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:
b2 + b - 2 = -4b + 4
b2 + b - 2 - 4 = -4b
b2 + b + 4b - 6 = 0
b2 + 5b - 6 = 0
Next, factor the quadratic equation:
b2 + 5b - 6 = 0
(b - 1)(b + 6) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 1) or (b + 6) must equal zero:
If (b - 1) = 0, b must equal 1
If (b + 6) = 0, b must equal -6
So the solution is that b = 1 or -6
Which of the following is not a part of PEMDAS, the acronym for math order of operations?
pairs |
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exponents |
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division |
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addition |
When solving an equation with two variables, 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.)