To find out the equation of the line we need two points
so
we take
(1,-3) and (2,-9)
step 1
Find the slope
m=(-9+3)/(2-1)
m=-6/1
m=-6
step 2
Find the equation in slope intercept form
y=mx+b
we have
m=-6
point (1,-3)
substitute
-3=-6(1)+b
solve for b
-3=-6+b
b=6-3
b=3
therefore
y=-6x+3
