Đáp án:
${a) \frac{-5}{4};\frac{3}{2}\\ b) x/x<1}$
Giải thích các bước giải:
${a)(3x-2)(4x+5)=0\\ \Leftrightarrow \left[\begin{array}{l}3x-2=0\\4x+5=0\end{array}\right.\\ \Leftrightarrow \left[\begin{array}{l}x=\frac{3}{2}\\x=\frac{-5}{4}\end{array}\right.\\ }$
Vậy S={${\frac{-5}{4};\frac{3}{2}}$}
${b)\frac{2x-3}{2}>\frac{8x-11}{6}\\ \Leftrightarrow \frac{6x-9}{6}-\frac{8x-11}{6}>0\\ \Leftrightarrow \frac{-2x+2}{6}>0\\ \Leftrightarrow \frac{-x+1}{3}>0\\ \Leftrightarrow -x+1>0 \Leftrightarrow x<1}$
Vậy S={x/x<1)}
