The equation of the plane containing the given point is A(x−1)+B(y+1)+C(z−2)=0...(i)
Applying the condition of perpendicularly to the plane given in Eq. (i) with the planes 2x+3y−2z=5 and x+2y−3z=8, we have 2A+3B−2C=0 and A+2B−3C=0
Solving these equations, we find A=−5C and B=4C.
Hence, the required equation is −5C(x−1)+4C(y+1)+C(z−2)=0
i.e., 5x−4y−z=7