Question

//This is a proof of 2+2 =5 same we can proof that 2+2= any number so never say 2+2 = 5 //
2+2 =4 // we know
2+2= 4 – 9/2 + 9/2
2+2= √(4 – 9/2)2 + 9/2
2+2= √(16 – 2*4*9/2 + (9/2)2) + 9/2
2+2= √16 – 36 + (9/2)2) + 9/2
2+2= √(-20 + (9/2)2) + 9/2
2+2= √(25 – 45 + (9/2)2) + 9/2
2+2= √(52) – 2*5*9/2 + (9/2)2) + 9/2
2+2= √(5 – 9/2)2 + 9/2
2+2= 5 – 9/2 + 9/2
2+2= 5 //proved

Answer 1

what kind of question is this what did u mean what to do this

Answer 2

You've written that,

$= > \sqrt{(5 - \frac{9}{2})^{2} } = 5 - \frac{9}{2}$

But, I hope that, you know :- (-x)² = x² and (+x)² = x². e.g. :- (-2)² = 4 and (+2)² = 4. This means that, square root gives two values, positive value and negative value. This is true for all the powers in the form 1/2n, where n can be 1, 2, 3, ....... So, friend, in this case (radical case), it is necessary to check the result that you get with the original equation that you started with. So, it is :-

$\sqrt{(5 - \frac{9}{2})^{2} } = + (5 - \frac{9}{2}) \: or \: - (5 - \frac{9}{2}$)

Now, only negative value will be considered, because, when you write 4 - (9/2) as √{4 - (9/2)}², 4 - (9/2) is negative, i.e. (- 1/2) and then you've done some mathematical operations inside the same root. So, it is obvious that, it will give you a negative value (which you've written in the form of a square root in the starting). Thus, + {5 - (9/2)} will be neglected and we will only take -{5 - (9/2)} in consideration. Then, on solving we will get a true statement, i.e. 2 + 2 = 4. You can check it. So, always think before validating Maths.

Hope this will help you and you will understand it.