If one side of a rectangle is reduced (1/5) and the other side is increased by 2 meters, a square is obtained, which is exactly equal to the area of the original rectangle, so how many square meters is the area of the original rectangle?
把一个长方形的一边减少(1/5)，另一边增加2米，就得到一个正方形，它与原来长方形的面积正好相等，那么原来长方形的面积是多少平方米．
<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">2 / (1/4)</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">10 / (4/5)</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">(25/2) * 8</gadget>
<output>100</output>

<result>100</result>