Point slope and slope intercept form

Y=mx+b is slope intercept form's formula

I'm going to convert to slope intercept after (y=mx+b)

the equation of aline that passes throuhg the point (x1,y1) and has a slope of m is
y-y1=m(x-x1)

the slope of the line that passes through the points (x1,y1) and (x2,y2) is
(y2-y1)/(x2-x1)

2. passes through (4,-1) and slope is -3
x1=4
y1=-1
m=-3

y-(-1)=-3(x-4)
y+1=-3(x-4)
y+1=-3x+12
y=-3x+11

other one
passes through (3,-6) and (-1,2)
slope between them is (2-(-6))/(-1-3)=(2+6)/(-4)=8/-4=-8/4=-2

a point is (-1,2)
x1=-1
y1=2
m=-2
y-2=-2(x-(-1))
y-2=-2(x+1)
y-2=-2x-2
y=-2x