( 5х - 1 )^2 + ( 12х + 1 )^2 = ( 13x - 1 )^2
( 5x - 1 )^2 = ( 13x - 1 )^2 - ( 12x + 1 )^2
( 5x - 1 )^2 = ( 13x - 1 + ( 12x + 1 ))•( 13x - 1 - ( 12x + 1 ))
( 5x - 1 )^2 = ( 13x - 1 + 12x + 1 )•( 13x - 1 - 12x - 1 )
( 5x - 1 )^2 = 25х•( Х - 2 )
25х^2 - 10х + 1 = 25х^2 - 50х
- 10х + 1 = - 50х
50х - 10х = - 1
40х = - 1
Х = - 1/40
Х = - 0,025
Ответ ( - 0,025 )