The school has a rectangular flowerbed, 6 meters long. When building the campus, the length of the flowerbed was increased by 3 meters, so the area of the flowerbed was increased by 12 square meters. What is the original area of the flowerbed in square meters?
学校有一个长方形花圃，长6米，在修建校园时，花圃的长增加了3米，这样花圃的面积就增加了12平方米，花圃原来的面积是多少平方米．
<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<result>24</result>