| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
Solve for x:
x2 - x - 2 = 0
| 9 or -9 | |
| -1 or 2 | |
| -1 or -2 | |
| 8 or -6 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
x2 - x - 2 = 0
(x + 1)(x - 2) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 1) or (x - 2) must equal zero:
If (x + 1) = 0, x must equal -1
If (x - 2) = 0, x must equal 2
So the solution is that x = -1 or 2
Solve for z:
z2 + 11z + 41 = -2z + 1
| 9 or 1 | |
| -5 or -8 | |
| -6 or -7 | |
| -2 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:
z2 + 11z + 41 = -2z + 1
z2 + 11z + 41 - 1 = -2z
z2 + 11z + 2z + 40 = 0
z2 + 13z + 40 = 0
Next, factor the quadratic equation:
z2 + 13z + 40 = 0
(z + 5)(z + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z + 5) or (z + 8) must equal zero:
If (z + 5) = 0, z must equal -5
If (z + 8) = 0, z must equal -8
So the solution is that z = -5 or -8
Which of the following expressions contains exactly two terms?
binomial |
|
polynomial |
|
quadratic |
|
monomial |
A monomial contains one term, a binomial contains two terms, and a polynomial contains more than two terms.
The dimensions of this cylinder are height (h) = 9 and radius (r) = 7. What is the surface area?
| 176π | |
| 168π | |
| 306π | |
| 224π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(72) + 2π(7 x 9)
sa = 2π(49) + 2π(63)
sa = (2 x 49)π + (2 x 63)π
sa = 98π + 126π
sa = 224π
What is 7a - 2a?
| a2 | |
| 9a2 | |
| 5a | |
| 5 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
7a - 2a = 5a