Question

Помогите решить X4-5x3+4x=0

Answer 1

$x^{4} -5 x^{3} +4x=0$
$(x^2-x)(x^2-4x-4)=0$
$x(x-1)(x^2-4x-4)=0$
$x_{1} =0$
$x-1=0$
$x_{2} =1$
$x^2-4x-4=0$
$D=16-4*(-4)=32$
$x_{3} = frac{4+ sqrt{32} }{2} = frac{4+ sqrt{16*2} }{2} = frac{4+4 sqrt{2} }{2} =2+2 sqrt{2}$
$x_{4} = frac{4- sqrt{32} }{2} =2-2 sqrt{2}$