Question

Evaluate using algebraic formula:

99²

Answer 1

99²

Let’s take it as (100 − 1)²

(100 − 1)² = (100)² − 2(100)(1) + (1)²   ...[Using (a − b)² = a² − 2ab + b²]

(100 − 1)² = 10,000 − 2(100) + 1

(100 − 1)² = 10,000 − 200 + 1

∴ (100 − 1)² = 9,801