Question

X+Y =700 , Y +Z=500 , X +Z=800 , x,y,z=?

Answer 1

x+y=700
y+z=500
x+z=800 => x=800-z
800-z+y=700=>y=700-800+z=-100+z
-100+z+z=500
2z=600=> z=300
y+300=500 ==> y=200
x+200=700 ==> x=500

S={500,200,300}