Method 1
[tex]\frac{4}{9}=\frac{28}{x}[/tex][tex]\begin{gathered} 4x=28\times9 \\ x=\frac{252}{4}=63 \end{gathered}[/tex]Method 2
[tex]\frac{4}{9}-\frac{28}{x}=0[/tex][tex]\frac{4x-252}{9x}=0[/tex][tex]\begin{gathered} 4x-252=0\times9x \\ 4x-252=0 \end{gathered}[/tex][tex]\begin{gathered} 4x=252 \\ x=\frac{252}{4}=63 \end{gathered}[/tex]Therefore, x=63.