2x−3=−7y+15=5z−9&2x+1=1y−1=−3z−9 S.D =b1×b2(a2⋅a1)⋅(b1⋅b2)a1=3,−15,9 b1=2,−7,5a2=−1,1,9 b2=2,1,−3a2−a1=−4,16,0b1×b2=i^22j^−71k^5−3=i^(16)−j^(−16)+k^(16)16(i^+j^+k^)b1×b2=163∴(a2−a1)⋅(b1−b2)=16[−4+16]=(16)(12) S.D. =163(16)(12)=43