| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.47 |
| Score | 0% | 69% |
Simplify (y + 5)(y - 8)
| y2 + 13y + 40 | |
| y2 + 3y - 40 | |
| y2 - 3y - 40 | |
| y2 - 13y + 40 |
To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:
(y + 5)(y - 8)
(y x y) + (y x -8) + (5 x y) + (5 x -8)
y2 - 8y + 5y - 40
y2 - 3y - 40
Breaking apart a quadratic expression into a pair of binomials is called:
normalizing |
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deconstructing |
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squaring |
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factoring |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
The dimensions of this cube are height (h) = 5, length (l) = 2, and width (w) = 9. What is the volume?
| 162 | |
| 80 | |
| 48 | |
| 90 |
The volume of a cube is height x length x width:
v = h x l x w
v = 5 x 2 x 9
v = 90
The formula for the area of a circle is which of the following?
a = π r |
|
a = π r2 |
|
a = π d |
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a = π d2 |
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.
Solve for b:
b2 - 11 = -5b + 3
| 2 or -7 | |
| 5 or -9 | |
| 4 or 2 | |
| 9 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:
b2 - 11 = -5b + 3
b2 - 11 - 3 = -5b
b2 + + 5b - 14 = 0
b2 + 5b - 14 = 0
Next, factor the quadratic equation:
b2 + 5b - 14 = 0
(b - 2)(b + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 2) or (b + 7) must equal zero:
If (b - 2) = 0, b must equal 2
If (b + 7) = 0, b must equal -7
So the solution is that b = 2 or -7