Question 86 (xviii)
Using suitable identities, evaluate the following:
(9.7)2−(0.3)2
We have, (9.7)2−(0.3)2=(9.7+0.3)(9.7−0.3)=10×9.4 =94 [using the identity, a2−b2=(a+b)(a−b)]
(103)2
Question 86 (ii)
(49)2
Question 86 (v)
(1005)2
Question 86 (iii)