The slope of the line thru these two points is given by:
1-(-1)
m = ------------ = -2/5
-3 - 2
Write down the slope-intercept form and then use it to find the specific equation applying here:
y = mx + b; but when x = -3, y = 1, so 1 = (-2/5)(-3) + b.
Then 1 = 6/5 + b, or 5/5 = 6/5 + b, which results in b = -1/5.
Then the equation of a line in slope-intercept form that passes through the points (-3, 1) and (2, -1) is y = (-2/5)x - 1/5.
