Question

Решите уравнение:(x^2 + 4x)(x^2+4x-17) = -60

Answer 1

$(x^2 + 4x)(x^2+4x-17) = -60,\ x^2 + 4x=t, \ t(t-17)=-60, \ t^2-17t+60=0, \ t_1=5, t_2=12; \ left [ {{x^2 + 4x=5,} atop {x^2 + 4x=12;} right. \ x^2+4x-5=0, \ x_1=-5, x_2=1, \ x^2+4x-12=0, \ x_3=-6, x_4=2.$