| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
The endpoints of this line segment are at (-2, 1) and (2, -5). What is the slope-intercept equation for this line?
| y = -1\(\frac{1}{2}\)x - 2 | |
| y = -1\(\frac{1}{2}\)x + 4 | |
| y = 2\(\frac{1}{2}\)x + 4 | |
| y = 2x + 4 |
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 -2. 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, -5) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-5.0) - (1.0)}{(2) - (-2)} \) = \( \frac{-6}{4} \)Plugging these values into the slope-intercept equation:
y = -1\(\frac{1}{2}\)x - 2
Solve for y:
-6y + 1 = -5 - y
| 1 | |
| 1\(\frac{2}{3}\) | |
| \(\frac{1}{5}\) | |
| 1\(\frac{1}{5}\) |
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.
-6y + 1 = -5 - y
-6y = -5 - y - 1
-6y + y = -5 - 1
-5y = -6
y = \( \frac{-6}{-5} \)
y = 1\(\frac{1}{5}\)
What is 2a8 - 6a8?
| 8 | |
| 12a8 | |
| -4a8 | |
| -4a16 |
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.
2a8 - 6a8 = -4a8
Breaking apart a quadratic expression into a pair of binomials is called:
normalizing |
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squaring |
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deconstructing |
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factoring |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
Simplify (7a)(7ab) + (3a2)(4b).
| 37a2b | |
| 37ab2 | |
| 61a2b | |
| 98a2b |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
(7a)(7ab) + (3a2)(4b)
(7 x 7)(a x a x b) + (3 x 4)(a2 x b)
(49)(a1+1 x b) + (12)(a2b)
49a2b + 12a2b
61a2b