The perimeter of a rectangle is 130 cm. If the length increases (2/7) and the width decreases (1/3), the perimeter of the new rectangle remains the same. So what is the area of the original rectangle in square centimetres?
一个长方形的周长是130厘米．如果长增加(2/7)，宽减少(1/3)，得到新的长方形的周长不变．那么原来长方形的面积是多少平方厘米．
<gadget id="calculator">130 / 2</gadget>
<output>65</output>

<gadget id="calculator">7 + 6</gadget>
<output>13</output>

<gadget id="calculator">6 / 13</gadget>
<output>6/13 = around 0.461538</output>

<gadget id="calculator">65 * (6/13)</gadget>
<output>30</output>

<gadget id="calculator">7 / 13</gadget>
<output>7/13 = around 0.538462</output>

<gadget id="calculator">65 * (7/13)</gadget>
<output>35</output>

<gadget id="calculator">30 * 35</gadget>
<output>1_050</output>

<result>1_050</result>