Question

Subtract the square of 21 from the square of 22 without actually calculating the squares. ​

Answer 1

Answer:

Given,

We need to Subtract the square of 21 from the square of 22 without actually calculating the squares.

Using the formula

${x}^{2} - {y}^{2} = (x + y)(x - y)$

We get...

$= > {(22)}^{2} - {(21)}^{2} \\ = >(22 + 21 )(22 - 21) \\ = > 43 \times 1 \\ = > 43.$

Answer 2

Answer:

22^2 - 21^2

= using identity a^2-b^2 = (a+b)(a-b)

= (22+21) (22-21)

= 43 × 1

= 43...