Resposta :
Resposta:
[tex]x^5-4x^4+2x^3+9x^2-12x+4=0\\\\\left(x-1\right)\left(x-2\right)^2\left(x^2+x-1\right)=0\\\\x-1=0\quad \mathrm{or}\quad \:x-2=0\quad \mathrm{or}\quad \:x^2+x-1=0\\\\x=1,\:x=2,\:x=\frac{-1+\sqrt{5}}{2},\:x=\frac{-1-\sqrt{5}}{2}[/tex]