| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.40 |
| Score | 0% | 68% |
The dimensions of this cube are height (h) = 9, length (l) = 6, and width (w) = 5. What is the surface area?
| 98 | |
| 110 | |
| 258 | |
| 96 |
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 6 x 5) + (2 x 5 x 9) + (2 x 6 x 9)
sa = (60) + (90) + (108)
sa = 258
Which of the following statements about math operations is incorrect?
all of these statements are correct |
|
you can add monomials that have the same variable and the same exponent |
|
you can subtract monomials that have the same variable and the same exponent |
|
you can multiply monomials that have different variables and different exponents |
You can only add or subtract monomials that have the same variable and the same exponent. For example, 2a + 4a = 6a and 4a2 - a2 = 3a2 but 2a + 4b and 7a - 3b cannot be combined. However, you can multiply and divide monomials with unlike terms. For example, 2a x 6b = 12ab.
If side x = 14cm, side y = 6cm, and side z = 9cm what is the perimeter of this triangle?
| 20cm | |
| 29cm | |
| 25cm | |
| 40cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 14cm + 6cm + 9cm = 29cm
What is 7a8 + 6a8?
| 13 | |
| 1 | |
| 42a16 | |
| 13a8 |
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.
7a8 + 6a8 = 13a8
Solve for a:
-9a - 4 = 9 - 7a
| -6\(\frac{1}{2}\) | |
| -1 | |
| 8 | |
| \(\frac{7}{9}\) |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.
-9a - 4 = 9 - 7a
-9a = 9 - 7a + 4
-9a + 7a = 9 + 4
-2a = 13
a = \( \frac{13}{-2} \)
a = -6\(\frac{1}{2}\)