Matrices And Determinants

If p \(\ne\) a, q \(\ne\) b, r \(\ne\) c and the system of equations

px + ay + az = 0

bx + qy + bz = 0

cx + cy + rz = 0

has a non-trivial solution, then the value of \(\frac{p}{p-a}+\frac{q}{q-b}+\frac{r}{r-c}\) is