Line 1 passes through (1, 0, 1) with direction (1,2,1). Point on line: (1+t,2t,1+t).
For projection Q of P(3, 2, 1): (t−2,2t−2,t)⋅(1,2,1)=0 gives 6t=6, so t=1.
Thus Q = (2, 2, 2).
Distance from Q to line 2 (passing through (9, 9, 5) with direction (3,2,−2)):
QR=(7,7,3).
QR×d=−20i+23j−7k.
∣QR×d∣=400+529+49=978.
∣d∣=17.
Distance = 17978=57.53≈7.59≈7.