First we use the slope formula:

m = 

where (x1,y1) = (-8, 2) 

and where (x2,y2) = (5, -7).

m = 

m = 

m =  = 

Then we use the point-slope formula:

y - y1 = m(x - x1)

where (x1,y1) = (-8, 2)

and m = 

y - y1 = m(x - x1)

y - 2 = (x - (-8))

y - 2 = (x + 8)

Multiply both sides by 13 to clear the fraction:

13(y - 2) = 13·(x + 8) 

13y - 26 = -9(x + 8)

13y - 26 = -9x - 72

9x + 13y = -46  < -- that's standard form.

or solve for y:

     13y = -9x - 46

      = x - 

     y = x -    < --- that's slope intercept form.

Edwin