We want to find the x value that makes the following equation true
[tex]\frac{10,000}{400}x=55[/tex]In order to solve the equation for x we want to "leave alone" the a on one side of the equation. In order to do that we just have to remember one simple rule: what we do on one side of the equal "=" is what we must do on the other side.
Step 1: taking 400 to the right side
[tex]\begin{gathered} \frac{10,000}{400}x=55 \\ \downarrow \\ 10,000x=55\cdot400 \end{gathered}[/tex]Step 2: taking 10,000 to the right side
[tex]\begin{gathered} 10,000x=55\cdot400 \\ \downarrow \\ x=\frac{55\cdot400}{10,000} \end{gathered}[/tex]