Reduce one side of a square by (1/5) and increase the other side by 4 meters to obtain a rectangle. This rectangle has the same area as the original square. So how many square meters is the area of the original square?
将一个正方形的一边减少(1/5)，另一边增加4米，得到一个长方形．这个长方形与原来正方形面积相等．那么原来正方形面积有多少平方米．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / (4/5)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/4) - 1</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 / (1/4)</gadget>
<output>16</output>

<gadget id="calculator">16 * 16</gadget>
<output>256</output>

<result>256</result>