What are the direction ratios of the line determined by the planes x−y+2z=1 andx+y−z=3?

[a] The intersection of given plane is x−y+2z−1+λ(x+y−z−3)=0 ⇒x(1+λ)+y(λ−1)+z(2−λ)−3λ−1=0 DR?s of normal to the above plane is (1+λ,λ−1,2−λ) By taking option (a) −1(1+λ)+3(λ−1)+2(2−λ)=0 ⇒−1−λ+3λ−3+4−2λ=0 ⇒0=0 Which is true.