If 'p' and 'q' are the coefficients of xa and xb respectively in (1+x)a+b, then
Using the property of determinants and without expanding.
∣∣ ∣∣b+cq+ry+xc+ar+pz+xa+bp+qx+y∣∣ ∣∣=2∣∣ ∣∣apxbqycrz∣∣ ∣∣