9514 1404 393
Answer:
- equation: y -1 = -4(x +1)
- y-intercept: -3
- slope-intercept equation: y = -4x -3
Explanation:
The slope of the line is found using the slope formula:
m = (y2 -y1)/(x2 -x1)
m = (-11 -1)/(2 -(-1)) = -12/3 = -4
Then the point-slope form of the equation for a line can be used to write the equation:
y -k = m(x -h) . . . . . line with slope m through point (h, k)
Using the first point, the equation is ...
y -1 = -4(x +1)
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Simplifying to slope-intercept form, we can find the y-intercept.
y = -4x -4 +1
y = -4x -3 . . . . . . . . slope-intercept form
The constant in this equation is the y-intercept: -3, point (0, -3).