For a rectangle, if the width remains the same, the length increases by 6 meters, and the area increases by 54 square meters. If the length remains the same, the width decreases by 3 meters, and the area decreases by 36 square meters, what is the original area of the rectangle?
一个长方形，如果宽不变，长增加6米，面积增加54平方米，如果，长不变，宽减少3米，面积减少36平方米，这个长方形原来的面积是多少？
<gadget id="calculator">36 / 3</gadget>
<output>12</output>

<gadget id="calculator">54 / 6</gadget>
<output>9</output>

<gadget id="calculator">12 * 9</gadget>
<output>108</output>

<result>108</result>