[" 21.Find the direction cosines of two lines which are connected by the relations "1+m+n=0" and "],[mn-2nl-21m=0]

Find the direction cosines of the two lines which are connected by the relation l+m+n=0,mn−2nl−2lm=0

Find the direction cosines of the two lines which are connected by the relations l + m + n = 0 an mn - 2nl - 2lm = 0.

Find the direction cosines of the two lines which are connected by th relations. l-5m+3n=0 and 7l^2+5m^2-3n^2=0

Find the direction cosines l + m + n of the two lines which are connected by the relation l+ m + n = 0 and mn – 2nl –2lm = 0.

Find the direction cosines of the two lines which are connected by the relations l-5m+3n=0,7l^(2)+5m^(2)-3n^(2)=0

Find the direction cosines of the two lines which are connected by the relations l-5m+3n=0 and 7l^(2)+5m^(2)-3n^(2)=0-

Find the direction cosines of the lines, connected by the relations: l+m+n=0 and 2l m+2ln-m n=0.