An equation of the plane passing through the line of intersection of the planes x+y+z=6and 2x+3y+4z+5=0 and passing through (1, 1, 1) is
2x+3y+4z=9
x+y+z=3
x+2y+3z=6
20x+23y+26z=69
Equation of any plane through the line of intersection of the given planes is
2x+3y+4z+5+λ(x+y+z−6)=0
It passes through( 1, 1, 1)
if (2+3+4+5)+λ(1+1+1−6)=0
⇒λ=14/3 and the required equation is therefore,
20x+23y+26z=69.