step 1
find the slope
we have the points
(-6,10) and (-3,-2)
m=(-2-10)/(-3+6)
m=-12/3
m=-4
step 2
find the equation in point slope form
y-y1=m(x-x1)
we have
m=-4
(x1,y1)=(-6,10)
substitute
y-10=-4(x+6)
step 3
convert to slope intercept form
isolate the variable y
y-10=-4x-24
y=-4x-24+10
y=-4x-14