| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.66 |
| Score | 0% | 73% |
Solve for x:
x2 - 8x + 18 = x - 2
| 5 or -5 | |
| 4 or 5 | |
| 8 or 7 | |
| 4 or -2 |
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:
x2 - 8x + 18 = x - 2
x2 - 8x + 18 + 2 = x
x2 - 8x - x + 20 = 0
x2 - 9x + 20 = 0
Next, factor the quadratic equation:
x2 - 9x + 20 = 0
(x - 4)(x - 5) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x - 4) or (x - 5) must equal zero:
If (x - 4) = 0, x must equal 4
If (x - 5) = 0, x must equal 5
So the solution is that x = 4 or 5
The formula for the area of a circle is which of the following?
a = π d |
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a = π r2 |
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a = π d2 |
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a = π r |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.
Which of the following is not a part of PEMDAS, the acronym for math order of operations?
exponents |
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division |
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addition |
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pairs |
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.)
If side x = 8cm, side y = 7cm, and side z = 10cm what is the perimeter of this triangle?
| 30cm | |
| 25cm | |
| 33cm | |
| 35cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 8cm + 7cm + 10cm = 25cm
The formula for volume of a cube in terms of height (h), length (l), and width (w) is which of the following?
h2 x l2 x w2 |
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lw x wh + lh |
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h x l x w |
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2lw x 2wh + 2lh |
A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.