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Questions | 5 | 5 |
Correct | 0 | 3.03 |
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Solve for z:
z2 - 6z - 7 = 0
5 or 2 | |
-1 or 7 | |
2 or -8 | |
4 or -9 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
z2 - 6z - 7 = 0
(z + 1)(z - 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z + 1) or (z - 7) must equal zero:
If (z + 1) = 0, z must equal -1
If (z - 7) = 0, z must equal 7
So the solution is that z = -1 or 7
A(n) __________ is to a parallelogram as a square is to a rectangle.
rhombus |
|
trapezoid |
|
quadrilateral |
|
triangle |
A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.
If the area of this square is 36, what is the length of one of the diagonals?
\( \sqrt{2} \) | |
6\( \sqrt{2} \) | |
8\( \sqrt{2} \) | |
4\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{36} \) = 6
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 62 + 62
c2 = 72
c = \( \sqrt{72} \) = \( \sqrt{36 x 2} \) = \( \sqrt{36} \) \( \sqrt{2} \)
c = 6\( \sqrt{2} \)
What is 3a + 8a?
11a | |
11a2 | |
11 | |
-5a2 |
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.
3a + 8a = 11a
The endpoints of this line segment are at (-2, -2) and (2, -4). What is the slope-intercept equation for this line?
y = 2x + 1 | |
y = -\(\frac{1}{2}\)x - 3 | |
y = \(\frac{1}{2}\)x + 2 | |
y = 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, -2) and (2, -4) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-4.0) - (-2.0)}{(2) - (-2)} \) = \( \frac{-2}{4} \)Plugging these values into the slope-intercept equation:
y = -\(\frac{1}{2}\)x - 3