Đáp án: x>-1,84
Giải thích các bước giải:
$\begin{array}{l}
m)\frac{{5x - 3}}{5} + \frac{{3x - 1}}{4} < \frac{{x\left( {2{x^2} + 3} \right)}}{2} - 5\\
\Rightarrow \frac{{4.\left( {5x - 3} \right) + 5.\left( {3x - 1} \right)}}{{20}} < \frac{{10.\left( {2{x^3} + 3x} \right) - 5.20}}{{20}}\\
\Rightarrow 20x - 12 + 15x - 5 < 20{x^3} + 30x - 100\\
\Rightarrow 20{x^3} - 5x + 117 > 0\\
\Rightarrow \left( {x + 1,84} \right).g\left( x \right) > 0\left( {g\left( x \right) > 0} \right)\\
\Rightarrow x > - 1,84
\end{array}$
