Đáp án+Giải thích các bước giải:
\(a.\\2x^2 -3x -|2x^2 +5|=11\\\Leftrightarrow 2x^2 - 3x -(2x^2 +5)=11\\\Leftrightarrow 2x^2 - 3x -2x^2 -5 =11\\\Leftrightarrow -3x =16\\\Leftrightarrow x=-\dfrac{16}{3}\\b.\\|5x -4| -2|x+2|=0\\\Leftrightarrow |5x-4|=2|x+2|\\\Leftrightarrow \left[ \begin{array}{l}5x-4=2(x+2)\\5x-4=-2(x+2)\end{array} \right.\\\Leftrightarrow \left[ \begin{array}{l}3x=8\\7x=0\end{array} \right.\\\Leftrightarrow \left[ \begin{array}{l}x=\dfrac{8}{3}\\x=0\end{array} \right.\)