| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.95 |
| Score | 0% | 59% |
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 |
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you can subtract monomials that have the same variable and the same exponent |
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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.
Find the value of b:
-9b + z = 7
5b - 9z = -5
| -\(\frac{29}{38}\) | |
| -\(\frac{8}{25}\) | |
| 1\(\frac{10}{11}\) | |
| 1\(\frac{1}{2}\) |
You need to find the value of b so solve the first equation in terms of z:
-9b + z = 7
z = 7 + 9b
then substitute the result (7 - -9b) into the second equation:
5b - 9(7 + 9b) = -5
5b + (-9 x 7) + (-9 x 9b) = -5
5b - 63 - 81b = -5
5b - 81b = -5 + 63
-76b = 58
b = \( \frac{58}{-76} \)
b = -\(\frac{29}{38}\)
The dimensions of this cube are height (h) = 5, length (l) = 1, and width (w) = 5. What is the volume?
| 180 | |
| 70 | |
| 25 | |
| 162 |
The volume of a cube is height x length x width:
v = h x l x w
v = 5 x 1 x 5
v = 25
If the base of this triangle is 2 and the height is 2, what is the area?
| 105 | |
| 75 | |
| 2 | |
| 27 |
The area of a triangle is equal to ½ base x height:
a = ½bh
a = ½ x 2 x 2 = \( \frac{4}{2} \) = 2
The endpoints of this line segment are at (-2, 4) and (2, 2). What is the slope-intercept equation for this line?
| y = -\(\frac{1}{2}\)x + 3 | |
| y = -3x - 1 | |
| y = 3x - 4 | |
| y = 1\(\frac{1}{2}\)x + 2 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is 3. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, 4) and (2, 2) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(2.0) - (4.0)}{(2) - (-2)} \) = \( \frac{-2}{4} \)Plugging these values into the slope-intercept equation:
y = -\(\frac{1}{2}\)x + 3