1) Using suitable identities find the following products:
a)  ( 2a + 3 ) ( 2a + 3 )
b)  ( 4x – y ) ( 4x – y )
c)  ( pq + 2 ) ( pq – 2 )
d)  ( 1x^2 - 16 ) ( 1x^2 - 16 )