\(X:\dfrac{3}{9}=\dfrac{7}{8}\)
\(X=\dfrac{7}{8}\times\dfrac{3}{9}\)
\(X=\dfrac{21}{72}\)
\(\left(X-21\times13\right):11=30\)
\(X-273=330\)
\(X=603\)
`x:3/9=7/8`
`x=7/8xx3/9`
`x=7/24`
`-------------`
`(x-21xx13):11=30`
`(x-273):11=30`
`x-273=30xx11`
`x-273=330`
`x=330-273`
`x=57`