Compute $103 \times 97$ using identities.

Compute $103 \times 97$ using identities.
  1. $9991$
  2. $10000$
  3. $9981$
  4. $9971$

Solution

$103 \times 97 = (100+3)(100-3) = 100^{2} - 3^{2} = 10000 - 9 = 9991$.

Asked in: IMO

Practice more ALGEBRAIC EXPRESSIONS AND IDENTITIES questions on Aicharya