Find the shortest distance between the lines

We know that
Shortest distance between the lines:
and
is
…(i)
The standard form of a pair of Cartesian lines is:
and 
And the given equations are:
and 
Comparing the given equations with the standard form, we get
x1 = -1, y1 = -1, z1 = -1; x2 = 3, y2 = 5, z2 = 7
a1 = 7, b1 = -6, c1 = 1; a2 = 1, b2 = -2, c2 = 1
Now, consider
⇒ 
⇒ 
⇒ 
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Next, consider
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⇒ From (i), we have
⇒ 