f(1)-f(-2) -10-8
First find the slope: m = -------------- = ---------- = -6
1-(-2) 3
Use the point-slope form of the eqn of a str line:
y-h = m(x-k), where (h,k) is any point on the line and m is the slope.
Here, one result is y-8 = -6(x-(-2)), or y-8 = -6(x+2).
This can of course be re-written in other forms.
