Square of a number which lies between 41 and 49

Square of a number which lies between 41 and 49

Proof: Any number from 41 to 49 can be represented as (50 – a). Taking the square of this number we have equation as:
\( (50-a)^{2} \) = \( 50^{2} \) - 2 \( \times \) 50 \( \times \) a + \( a^{2} \) = 2500 - 100a + \( a^{2} \) = 100(25-a) + \( a^{2} \) = (25-a) / \( a^{2} \)

https://www.hamaraguru.com/assets/files/2018-01-12/1515738503-807268-imgur-22.jpeg
Steps for better understand:
Step 1: 46 is 4 less than 50. So a=4. Obtain the square of this digit.  Obtain the square of 4 to get 16. This forms the 2nd part of the answer.
Step 2: Subtract 4 from 25 to get 21. This forms the 1st part of the answer.
So, \( 46^{2} \) = 2116

One more Example:
https://www.hamaraguru.com/assets/files/2018-01-12/1515738645-32716-imgur-23.jpeg