Mathematics

Problem

10. Find the values of

p

so that the lines

\frac{1-x}{3}=\frac{7 y-14}{2 p}=\frac{z-3}{2}

and

\frac{7-7 x}{3 p}=\frac{y-5}{1}=\frac{6-z}{5}

are at right angles.