Find 5 consecutive whole numbers if it is known that the sum of the squares of the first 3 numbers is equal to the sum of the squares of the last 2 numbers.

Answer 1

let the numbers be x-2, x-1, x, x+1, x+2
Then you know that
(x-2)^2 + (x-1)^2 + x^2 = (x+1)^2 + (x+2)^2
Now find x, and you have the middle number.