Question

Find the value of $97\times 103$ using a suitable algebraic identity.

• A. 9999
• B. 1111
• C. 9991
• D. 8999

Answer 1

Answer: (C)

9991

$97\times 103$ can be rewritten as $(100-3)(100+3)$.

We know, $(a+b)(a-b)=a^2-b^2$.

$\therefore 97\times 103={\left(100\right)}^2-{\left(3\right)}^2$

$=10000-9$

$=9991$