Solve the equation: ((200+x)/20)=((120+x)/18).
解方程：((200+x)/20)=((120+x)/18)．
<gadget id="calculator">200 / 20</gadget>
<output>10</output>

<gadget id="calculator">120 / 18</gadget>
<output>20/3 = around 6.666667</output>

<gadget id="calculator">10 - (20/3)</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/18) - (1/20)</gadget>
<output>1/180 = around 0.005556</output>

<gadget id="calculator">(10/3) / (1/180)</gadget>
<output>600</output>

<result>600</result>