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

$\large \underline{ \underline{ \sf \: Solution : \: \: \: }}$

We know that ,

$\large \sf \fbox{ \fbox{ {(a)}^{2} - {(b)}^{2} = (a + b)(a - b)}}$

So ,

$\sf \implies {(22)}^{2} - {(21)}^{2} \\ \\ \sf \implies {(22 + 21)(22 - 21) }\\ \\\sf \implies 43 \times 1 \\ \\\sf \implies 43</p><p></p><p>$

Hence , 43 is the required value