Đáp án:
Giải thích các bước giải:
a) $4x-8+4-\frac{2x}{x^2}+1=0\\\Leftrightarrow 4x-3-\frac{2}{x}\\\Leftrightarrow 4x^2-3x-2=0\\\Leftrightarrow x=\frac{3\pm \sqrt{41}}{8}$
b) $x^2+2x+\frac{1}{x}+1=0\\\Leftrightarrow x^3+2x^2+x+1=0\\\Leftrightarrow x=\frac{1}{3}(-2-\sqrt[3]{\frac{2}{25-3\sqrt{69}}}-\sqrt[3]{\frac{1}{2}(25-3\sqrt{69})})$
c) $2x-\frac{5}{x}+5=3\\\Leftrightarrow 2x-\frac{5}{x}+2=0\\\Leftrightarrow 2x^2+2x-5=0\\\Leftrightarrow x=\frac{-1\pm \sqrt{11}}{2}$