In a rectangle, if one of the long sides is increased by 5 cm and the width remains the same, the area will increase by 25 cm2; if one of the broad sides is increased by 8 cm and the length remains the same, the area will be increased by 64 cm2. Do you know the area of the original rectangle?
有一个长方形，如果一条长边增加5厘米，宽不变，面积就增加25平方厘米；如果一条宽边增加8厘米，长不变，面积就增加64平方厘米．你知道原来长方形的面积是多少吗？
<gadget id="calculator">25 / 5</gadget>
<output>5</output>

<gadget id="calculator">64 / 8</gadget>
<output>8</output>

<gadget id="calculator">5 * 8</gadget>
<output>40</output>

<result>40</result>