| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.27 |
| Score | 0% | 65% |
The endpoints of this line segment are at (-2, -1) and (2, 7). What is the slope-intercept equation for this line?
| y = -2x + 1 | |
| y = -x - 1 | |
| y = 2x + 3 | |
| y = 2x - 3 |
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, -1) and (2, 7) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(7.0) - (-1.0)}{(2) - (-2)} \) = \( \frac{8}{4} \)Plugging these values into the slope-intercept equation:
y = 2x + 3
Which of the following is not true about both rectangles and squares?
the lengths of all sides are equal |
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the area is length x width |
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all interior angles are right angles |
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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 7a4 + 8a4?
| 15a8 | |
| -1 | |
| -a8 | |
| 15a4 |
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.
7a4 + 8a4 = 15a4
If a = 2, b = 6, c = 5, and d = 7, what is the perimeter of this quadrilateral?
| 25 | |
| 20 | |
| 6 | |
| 27 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 2 + 6 + 5 + 7
p = 20
Which of the following statements about a triangle is not true?
perimeter = sum of side lengths |
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sum of interior angles = 180° |
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exterior angle = sum of two adjacent interior angles |
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area = ½bh |
A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.