Given →a=x^i+y^j+2^k,→b=^i−^j+^k,→c=^i+2^j;(→a∧→b)=π2,→a.→c=4 then
If →a,→b and →c are three non-coplanar vectors, then (→a+→b+→c)⋅[(→a+→b)×(→a+→c)] equals