x(-1,3) y(3,0) z(-1,-2)
xy
m = (3 + 1)/(0 - 3) = 4/-3 = -4/3
y - 3 = -4/3(x + 1)
y - 3 = -4/3x - 4/3
xy: y = -4/3x + 5/3
yz
m = (0 + 2)/(3 + 1) = 2/4 = 1/2
y = 1/2(x - 3)
yz: y = 1/2x - 3/2
xz
m = (3 + 2)/(-1 + 1) = 5/0 = undefined
y - 3 = undefined(x + 1)
xz: x = -1
xy: y = -4x/3 + 5/3
yz: y = x/2 - 3/2
xz: x = -1
