( x^2 + 4x )( x^2 + 4х - 17 ) + 60 = 0
х^2 + 4х = а
а( а - 17 ) + 60 = 0
а^2 - 17а + 60 = 0
D = 289 - 240 = 49 ; √ D = 7
a1 = ( 17 + 7 ) : 2 = 12
a2 = ( 17 - 7 ) : 2 = 5
x^2 + 4x = 12
x^2 + 4x - 12 = 0
D = 16 + 48 = 64 ; √ D = 8
x1 = ( - 4 + 8 ) : 2 = 2
x2 = ( - 4 - 8 ) : 2 = - 6
x^2 + 4x = 5
x^2 + 4x - 5 = 0
D = 16 + 20 = 36 ; √ D = 6
x1 = ( - 4 + 6 ) : 2 = 1
x2 = ( - 4 - 6 ) : 2 = - 5
Ответ 2 ; - 6 ; 1 ; - 5