For a rectangle, if the length remains the same and the width increases by 5 cm, the area increases by 60 cm2; if the width remains the same and the length decreases by 4 cm, the area decreases by 40 cm2. What is the area of the original rectangle in square centimeters?
一个长方形，如果长不变，宽增加5厘米，则面积增加60平方厘米；如果宽不变，长减少4厘米，则面积减少40平方厘米．原长方形的面积是多少平方厘米．
<gadget id="calculator">60 / 5</gadget>
<output>12</output>

<gadget id="calculator">40 / 4</gadget>
<output>10</output>

<gadget id="calculator">12 * 10</gadget>
<output>120</output>

<result>120</result>