(i) 1012 – 992
= (101 + 99) (101 – 99) (Using given identity)
= (200) (2)
= 400
(ii) (10.3)2 – (9.7)2
= (10.3 + 9.7) (10.3 – 9.7) (Using given identity)
= (20) (0.6)
= 12
(iii) 1532 – 1472
= (153 + 147) (153 – 147) (Using given identity)
= (300) (6)
= 1800