How do you write the equation of a line in point slope form and slope intercept form given points (3, -8) (-2, 5)?

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Answer 1 · 2015-05-27T11:56:47

Given the points $(3,-8)$ and $(-2,5)$
both the point-slope form and the slope-intercept form require that we first determine the slope.

The slope can be calculated as
$m = (Delta y)/(Delta x) = (5-(-8))/(-2-3) = - 13/5$

Using the slope $m=-13/5$ and the point $(3,-8)$
the slope-point form ( $y-y_1 = m(x-x_1)$ ) is

$y-(-8) = -13/5(x-3)$
or
$y+8 = -13/5(x-3)$

The slope-point form can be converted into the slope-intercept form ( $y=mx+b$ ) by some minor re-arranging of terms:
$y+8 = -13/5(x-3)$

$rarr y = -13/5 x +39/5 -8$

$rarr y = -13/5x -1/8$