Question

Find the product by using the formula.

(10) 54 × 46

Answer 1

54 × 46
54 = 50 + 4
46 = 50 − 4
∴ 54 × 46 = (50 + 4) (50 − 4)
The expression (50 + 4) (50 − 4) is of the form (a + b) (a − b).
Thus, we can use the identity (a + b) (a − b) = a² − b² .
∴ 54 × 46 = (50 + 4) (50 − 4)
= (50)² − (4)²
= 2500 − 16
= 2484