rectangular field has a perimeter of 48 meters. Its width is 8 meters, what is its length? (solution by equation)
一块长方形的地，周长为48米．它的宽是8米，它的长是多少米？(用方程解)
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">48 - 16</gadget>
<output>32</output>

<gadget id="calculator">32 / 2</gadget>
<output>16</output>

<result>16</result>