Hello,
This method is correct!
[tex] \dfrac{4}{5} *x+ \dfrac{7}{2} = \dfrac{3}{10} \\
==\textgreater\ \dfrac{5}{4}*( \dfrac{4}{5} *x+ \dfrac{7}{2}) = \dfrac{5}{4}* \dfrac{3}{10} \\
==\textgreater\ \dfrac{5}{4}* \dfrac{4}{5} *x+ \dfrac{5}{4}*\dfrac{7}{2}=\dfrac{5}{4}* \dfrac{3}{10} \\
==\textgreater\ x+ \dfrac{35}{8} = \dfrac{3}{8} \\
==\textgreater\ x+ \dfrac{35}{8}-\dfrac{35}{8} = \dfrac{3}{8} -\dfrac{35}{8}\\
==\textgreater\ x = -\dfrac{32}{8}\\
Maybe\ this\ line \ is\ missing\\
x=-4
[/tex]