……(1)

……(2)

a₁ = 4, b₁ = 4, c₁ = – 5

a₂ = 7, b₂ = 1, c₂ = 3

x₁ = 5, y₁ = 7, z₁ = – 3

x₂ = 8, y₂ = 4, z₂ = 5

the condition for two line to be coplanar,

= 0

=

=

= 3(12 + 5) + 3(12 + 35) + 8(4 – 28)

= 3 × 17 + 3 × 47 + 8 × (–24)

= 51 + 141 – 192

= 192 – 192

= 0

The lines are coplanar to each other .