Question 86 (xvii)
Using suitable identities, evaluate the following:
(69.3)2−(30.7)2
We have, (69.3)2−(30.7)2=(69.3+30.7)(69.3−30.7)=100×38.6 =3860 [using the identity, (a+b)(a−b)=a2−b2]
Using a suitable identity, evaluate the following:
Question 86 (xiii)
(9.9)2
Question 86 (v)
(1005)2
Question 86 (iv)
(98)2