jmc

Turning the division sign into multiplication and simplifying, we have $$\begin{array}{rl}\frac{1}{x}+\frac{2}{x}\cdot \frac{x}{4}& =.75\\ \Rightarrow \frac{1}{x}+\frac{1}{2}& =.75\\ \Rightarrow \frac{1}{x}& =.25\\ \Rightarrow x& =\boxed{4}.\end{array}$$