3d Geometry

If the equation of the plane containing the line

\(x+2 y+3 z-4=0=2 x+y-z+5\) and perpendicular to the plane

$\vec{r}=(\hat{i}-\hat{j})+\lambda(\hat{i}+\hat{j}+\hat{k})+\mu(\hat{i}-2 \hat{j}+3 \hat{k})$

is $a x+b y+c z=4$, then \((a-b+c)\) is equal to :