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normally to find the intersecting line 3 planes will be provided but here only 2 planes are given, though i have to find 3 variables. please some one help me to find the equation of line of intersection

Find the acute angle between the planes with equations $$ x-2 y+z-9=0 \quad \text { and } \quad x+y-z+2=0 $$ The planes meet in the line $l$, and $A$ is the point on $/$ whose position vector is $p \mathbf{i}+q \mathbf{j}+\mathbf{k}$.
(i) Find $p$ and $q$.
(ii) Find a vector equation for $l$.

Normally to find the intersecting line 3 planes will be provided but here only 2 planes are given, though i have to find 3 variables. please some one help me to find the equation of line of intersection