Answer :
[tex]\frac{4}{5}=\frac{28}{x}\ \ \ \ |multiply\ by\ x\ each\ side\\\\
\frac{4}{5}x=28\ \ \ \ |Multiply\ by\ 5\ each\ side\\\\
4x=140\ \ \ |:4\\\\
x=35\\\\\\
Cross\ multiplication\ method:\\\\
4x=28*5\\\\
4x=140\ \ \ |:4\\\\
x=35
[/tex]