A parallelogram. If the bottom increases by 2cm, the height remains the same, the area increases by 4cm**2; if the height decreases by 1cm, the bottom remains the same, the area decreases by 3cm**2. What is the area of the original parallelogram?
一个平行四边形．若底增加2cm，高不变，面积增加4cm**2；若高减少1cm，底不变，面积就减少3cm**2．原平行四边形的面积是多少？
<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<result>6</result>