Write a linear function f with the values f(-2)=8 f(1)= -10

                                         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.