Solución

a. x=1+t,y=2+2t,z=3+3t,tRx=1+t,y=−2+2t,z=3+3t, t\isin\Reals
b. x11=y+22=z33\frac{x−1}{1}=\frac{y+2}{2}=\frac{z−3}{3}
c. (0,4,0)(0,−4,0)