A rectangular vegetable field. The ratio of length to width is 7:3. If the width is increased by 16 meters, it becomes a square. What is the area of this vegetable field in square meters?
一块长方形的菜地．长和宽的比是7：3，如果宽增加16米，就变成了正方形，原来这块菜地的面积是多少平方米？
<gadget id="calculator">7 / 3</gadget>
<output>7/3 = around 2.333333</output>

<gadget id="calculator">(7/3) - 1</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">16 / (4/3)</gadget>
<output>12</output>

<gadget id="calculator">(7/3) * 12 * 12</gadget>
<output>336</output>

<result>336</result>