4( 5х - 40 ) + х = ( 13х - 113 )2 + 1
20х - 160 + х = 26х - 226 + 1
20х + х - 160 = 26х - 226 + 1
21х - 160 = 26х - 226 + 1
21х - 160 = 26х - 225
21х - 26х - 160 = - 225
- 5х - 160 = - 225
- 5х = - 225 + 160
- 5х = - 65
х = - 65 ÷ ( - 5 )
х = 13.
Ответ: х = 13.