| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.43 |
| Score | 0% | 69% |
Solve for y:
y2 + 17y + 72 = 0
| -3 or -9 | |
| 5 or 3 | |
| -8 or -9 | |
| 2 or -4 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
y2 + 17y + 72 = 0
(y + 8)(y + 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 8) or (y + 9) must equal zero:
If (y + 8) = 0, y must equal -8
If (y + 9) = 0, y must equal -9
So the solution is that y = -8 or -9
The formula for the area of a circle is which of the following?
a = π r |
|
a = π r2 |
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a = π d2 |
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a = π d |
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 expressions contains exactly two terms?
binomial |
|
quadratic |
|
monomial |
|
polynomial |
A monomial contains one term, a binomial contains two terms, and a polynomial contains more than two terms.
If b = -8 and y = 6, what is the value of 9b(b - y)?
| -42 | |
| -384 | |
| 128 | |
| 1008 |
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.)
9b(b - y)
9(-8)(-8 - 6)
9(-8)(-14)
(-72)(-14)
1008
Simplify (9a)(5ab) - (2a2)(2b).
| 56a2b | |
| 49a2b | |
| 41a2b | |
| 49ab2 |
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.
(9a)(5ab) - (2a2)(2b)
(9 x 5)(a x a x b) - (2 x 2)(a2 x b)
(45)(a1+1 x b) - (4)(a2b)
45a2b - 4a2b
41a2b