| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
Simplify (5a)(8ab) - (5a2)(7b).
| 156a2b | |
| 75ab2 | |
| 5a2b | |
| 156ab2 |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
(5a)(8ab) - (5a2)(7b)
(5 x 8)(a x a x b) - (5 x 7)(a2 x b)
(40)(a1+1 x b) - (35)(a2b)
40a2b - 35a2b
5a2b
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 c:
c2 + 16c + 78 = -2c - 3
| -9 | |
| 2 or -4 | |
| -6 or -9 | |
| 6 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:
c2 + 16c + 78 = -2c - 3
c2 + 16c + 78 + 3 = -2c
c2 + 16c + 2c + 81 = 0
c2 + 18c + 81 = 0
Next, factor the quadratic equation:
c2 + 18c + 81 = 0
(c + 9)(c + 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, (c + 9) must equal zero:
If (c + 9) = 0, c must equal -9
So the solution is that c = -9
A(n) __________ is to a parallelogram as a square is to a rectangle.
quadrilateral |
|
triangle |
|
rhombus |
|
trapezoid |
A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.
Breaking apart a quadratic expression into a pair of binomials is called:
squaring |
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factoring |
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deconstructing |
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normalizing |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.