Let a→=i^+j^ and b→=2i^−k^ then the point of intersection of the lines r→×a→=b→×a→  and r→×b→=a→×b→ is

let  r→×a→=b→×a→ ⇒(r→−b→)×a→=0→⇒r→=b→+ta→Similarly, other line r→=a→+kb→  where t and k are scalars.now  a→+kb→=b→+ta→⇒ t=1,k=1∴ r→=a→+b→=i^+j^+2i^−k^=3i^+j^−k^i.e.  (3, 1, -1)