Tìm x,y,z thuộc Q biết:|x-2/3|+|x+y+3/4|+|y-z-5/6|=0

x−23+x+y+34+y−z−56=0 mà x−23≥0;x+y+34≥0;y−z−56≥0

⇒x−23=0x+y+34=0y−z−56=0⇒x=23y=−34−xz=y−56⇒x=23y=−1712z=−94 

Vậy x=23; y=−1712; z=−94