Question

square of 98.9 without multiplicatiin​

Answer 1

Answer:

9781.21

Step-by-step explanation:

Given :

To find the value of square of 98.9 without performing actual multiplication,.

Solution :

We know that,

(a - b)² = a² - 2ab + b²

let a = 100 & b = 1.1

such that,

(a - b) = 98.9

98.9² = (100.0 - 1.1)²

= (100)² - 2(100)(1.1) + (1.1)²

= 10,000 - 220 + 1.21 = 9781.21