Show that
(4pq + 3q)2 - (4pq - 3q)2 = 48pq2 Â Â Â
        Â
LHSÂ Â Â Â Â Â = (4pq + 3q)2 - (4pq - 3q)2 = 48pq2
      = [(4pq)2 + 2(4pq)(3q) + (3q)2 ]  -[(4pq)2 - 2(4pq)(3q) + (3q)2 ]
           = 16p2q2 + 24pq2 + 9q2 - (16p2q2 - 24pq2 + 9q2 ]
           = (16 - 26)p2q2 + (24 + 24)pq2 + (9 -9)q2
           = (0)p2q2 + 48pq2 + (0)q2
           = 48pq2 = RHS
Since, LHS = RHS
∴    (4pq + 3q)2 - (4pq - 3q)2 = 48pq2