X^4 -8x^3-4x^2+16x+4=0

Question

X^4 -8x^3-4x^2+16x+4=0

Answer 1

X³-4x²-16x+64=0
х²(х-4)-16(х-4)=0
(х-4)(х²-16)=0
(х-4)(х-4)(х+4)=0
х-4=0 или х+4=0
х=4 х=-4
Ответ :-4 и 4