Question 5877
first find the slope:
{{{(y-y1)/(x-x1)}}}
{{{(-8-(-4))/(9-7)}}}
{{{-4/2}}}
slope = -2

Then use y=mx+b and substitute one set of points into the equation:
-8=-2(9)+b
-8=-18+b
b=10

so the equation is y=-2x+10