Let ω =ei2π/3, and a, b, c, x, y, z be non-zero complex numbers such thata+b+c=xa+bω+cω2=ya+bω2+cω=z.Then the value of |x|2+|y|2+|z|2|a|2+|b|2+|c|2 is
Let a,b,c,be any real numbers. Suppose that there are real numbers x, y, z not all zero such that x= cy +bz, y=az + cx and z = bx +ay. Then , a2 + b2+ c2+ 2abc is equal to