\(\frac{3}{4x}+\frac{7}{2}\times5x-4=\frac{5}{4}\)
\(\Rightarrow \frac{3}{4x}+\frac{35x}{2}=\frac{5}{4}+4\)
\(\Rightarrow \frac{3\,+\,70x^2}{4x}=\frac{5\,+\,16}{4}\)
\(\Rightarrow \frac{73x^2}{4x}=\frac{21}{4}\)
\(\Rightarrow\) \(73x^{2-1}=21\)
\(\Rightarrow 73x=21\)
\(\Rightarrow x=\frac{21}{73}\)