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)]
Question 86 (xix)
(132)2−(68)2
Question 86 (xxi)
(729)2−(271)2
Question 86 (xiii)
(9.9)2
Question 86 (iii)
(103)2