Simple...
you have: (7,-7) and (6,-5)
Using [tex] \frac{ y_{1}- y_{2} }{ x_{1}- x_{2} } [/tex] to find slope--->>>
[tex] \frac{-7--5}{7-6} = \frac{-2}{1} [/tex]
=-2
m=-2
Using y=mx+b to find the equation of the line-->>(Use any of the coordinates)
(7,-7)
-7=-2(7)+b
-7=-14+b
-7=-14+b
+14 +14
7=b
y=-2x+7
Thus, your answer.