| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.42 |
| Score | 0% | 68% |
The dimensions of this cube are height (h) = 5, length (l) = 2, and width (w) = 4. What is the surface area?
| 198 | |
| 76 | |
| 64 | |
| 228 |
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 2 x 4) + (2 x 4 x 5) + (2 x 2 x 5)
sa = (16) + (40) + (20)
sa = 76
Simplify 9a x 8b.
| 72a2b2 | |
| 17ab | |
| 72\( \frac{a}{b} \) | |
| 72ab |
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 x 8b = (9 x 8) (a x b) = 72ab
Which of the following is not true about both rectangles and squares?
the area is length x width |
|
the lengths of all sides are equal |
|
all interior angles are right angles |
|
the perimeter is the sum of the lengths of all four sides |
A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s2).
What is 8a - 6a?
| 48a | |
| 14a2 | |
| 2a2 | |
| 2a |
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.
8a - 6a = 2a
Simplify (8a)(9ab) - (9a2)(2b).
| 90a2b | |
| 90ab2 | |
| -54ab2 | |
| 54a2b |
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.
(8a)(9ab) - (9a2)(2b)
(8 x 9)(a x a x b) - (9 x 2)(a2 x b)
(72)(a1+1 x b) - (18)(a2b)
72a2b - 18a2b
54a2b