L1:6x+7=7y−6=1z−0
Any point on it a1(−7,6,0) and L1 is parallel to b1(−6,7,1)
L2:−2x−7=1y−2=1z−6
Any point on it a2(7,2,6) and L2 is parallel to b2(−2,1,1)
Shortest distance between L1 and L2
=b1×b2(a2−a1).(b1×b2)=9+4+16(−14,4,−6).(3,2,4)
=229 .