Joy X. answered 08/20/20
Experienced Math tutor(SAT/ACT, high school and college math )
xA+yB+zV+uD=0
solve the system of equations, you can get x=(-5/3)u,y=u/3,z=-u, that means you have infinity many solutions.
You can pick one answer : u=-3,x=5,y=-1,z=3
5A-B+3C-3D=0