| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.39 |
| Score | 0% | 68% |
If a = 9, b = 9, c = 3, and d = 6, what is the perimeter of this quadrilateral?
| 15 | |
| 11 | |
| 27 | |
| 21 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 9 + 9 + 3 + 6
p = 27
A trapezoid is a quadrilateral with one set of __________ sides.
equal angle |
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parallel |
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equal length |
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right angle |
A trapezoid is a quadrilateral with one set of parallel sides.
Which of the following is not required to define the slope-intercept equation for a line?
y-intercept |
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x-intercept |
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slope |
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\({\Delta y \over \Delta x}\) |
A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.
Solve for b:
b2 + 5b - 71 = 4b + 1
| 6 or 3 | |
| 8 or -9 | |
| 8 or 2 | |
| 8 or -4 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
b2 + 5b - 71 = 4b + 1
b2 + 5b - 71 - 1 = 4b
b2 + 5b - 4b - 72 = 0
b2 + b - 72 = 0
Next, factor the quadratic equation:
b2 + b - 72 = 0
(b - 8)(b + 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 8) or (b + 9) must equal zero:
If (b - 8) = 0, b must equal 8
If (b + 9) = 0, b must equal -9
So the solution is that b = 8 or -9
A quadrilateral is a shape with __________ sides.
2 |
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4 |
|
3 |
|
5 |
A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.