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

The answer to this question is 43

${22}^{2} - {21}^{2} \\ on \: comparing \: with \\ {x }^{2} - {y}^{2} = (x + y)(x - y) \\ {22 }^{2} - {21}^{2} = (22 + 21)(22 - 21) \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 43 \times 1 = 43$