In general, any equation like [tex] ax=b [/tex] (assuming [tex] a \neq 0[/tex]) is solved by
[tex] x= \dfrac{b}{a} [/tex]
So, in your case, the solution is
[tex] x = \dfrac{\frac{1}{5}}{\frac{3}{4}} [/tex]
Dividing by a fraction means to multiply by the inverse of that fraction:
[tex] \dfrac{\frac{1}{5}}{\frac{3}{4}} = \dfrac{1}{5} \cdot \dfrac{4}{3} = \dfrac{4}{15} [/tex]
