The given equation is
[tex]J=\frac{Rs6}{u}[/tex]Multiplying by u on both sides, we get
[tex]Ju=\frac{Rs6}{u}\times u[/tex][tex]Ju=Rs6[/tex]Dividing by s6, we get
[tex]\frac{Ju}{s6}=\frac{Rs6}{s6}[/tex][tex]\frac{Ju}{s6}=R[/tex]Hence the value for R is
[tex]R=\frac{Ju}{s6}[/tex]