Question

丨X丨=2,丨y丨=3,丨z丨=4,且x>y>z,求x+y+z的值.

Answer 1

丨X丨=2,丨y丨=3,丨z丨=4,且x>y>z

则：x=2,y=-3,z=-4

或 x=-2,y=-3,z=-4

所以,x+y+z=-5 或x+y+z=-9