If one side of a square is reduced by 10% and the other side is increased by 2 decimeters, a rectangle is obtained. The area of this rectangle is equal to the area of the original square. What is the length of the sides of the original square?
一个正方形的一边减少10%，另一边增加2分米，得到一个长方形，这个长方形的面积与原正方形的面积相等，原正方形的边长是多少分米．
<gadget id="calculator">1.8 / 0.1</gadget>
<output>18</output>

<result>18</result>