| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.10 |
| Score | 0% | 62% |
The dimensions of this cube are height (h) = 7, length (l) = 1, and width (w) = 1. What is the surface area?
| 70 | |
| 142 | |
| 30 | |
| 258 |
The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):
sa = 2lw + 2wh + 2lh
sa = (2 x 1 x 1) + (2 x 1 x 7) + (2 x 1 x 7)
sa = (2) + (14) + (14)
sa = 30
If the base of this triangle is 6 and the height is 8, what is the area?
| 24 | |
| 82\(\frac{1}{2}\) | |
| 48 | |
| 63 |
The area of a triangle is equal to ½ base x height:
a = ½bh
a = ½ x 6 x 8 = \( \frac{48}{2} \) = 24
What is 6a + 6a?
| 12a2 | |
| 36a2 | |
| 36a | |
| 12a |
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.
6a + 6a = 12a
Simplify (y + 1)(y - 9)
| y2 + 10y + 9 | |
| y2 - 10y + 9 | |
| y2 - 8y - 9 | |
| y2 + 8y - 9 |
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 + 1)(y - 9)
(y x y) + (y x -9) + (1 x y) + (1 x -9)
y2 - 9y + y - 9
y2 - 8y - 9
Solve for x:
x2 - 14x + 49 = 0
| 9 or 3 | |
| 3 or -8 | |
| 7 | |
| 6 or -7 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
x2 - 14x + 49 = 0
(x - 7)(x - 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, (x - 7) must equal zero:
If (x - 7) = 0, x must equal 7
So the solution is that x = 7