a: \(\Leftrightarrow x^3-27+5x+x^3-6x=0\)
\(\Leftrightarrow2x^3-x-27=0\)
hay \(x\in\left\{2.45\right\}\)
b: \(\Leftrightarrow x^2+x-92-x^2-7x-12=17\)
=>-6x-104=17
=>-6x=121
hay x=-121/6
c: \(\Leftrightarrow2x^2-11x+12-2x^2+3x+35=34\)
=>-8x+47=34
=>-8x=-13
hay x=13/8
