Solving the system of the two equations for z we get
x = 4 - (19/2)z
y = 2 - 8z
z =z
That is a vector parallel to the intersection of the two planes
is u =< -19/2 , -8, 1 > or any scalar multiple
say n = < -19, -16, 2 >
The plane passing through the origin ( 0, 0, 0 )
has equation -19x -16y +2z =0