\(\sqrt{\dfrac{9}{4}}-\left|2x+1\right|=0,75\\ \Leftrightarrow1,5-\left|2x+1\right|=0,75\\ \Leftrightarrow\left|2x+1\right|=0,75\\ \Leftrightarrow\left[{}\begin{matrix}2x+1=0,75\\2x+1=-0,75\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}2x=-0,25\\2x=-1,75\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-0,125\\x=-0,875\end{matrix}\right.\)