The ratio of the length to the width of a rectangle is 7:2. If the length is reduced by 5 cm and the width is increased by 5 cm, the area is increased by 100 cm2. What is the area of the original rectangle in cm2?
一个长方形的长和宽的比是7：2，如果长减少5厘米，宽增加5厘米，则面积增加100平方厘米，那么原来长方形面积是多少平方厘米．
<gadget id="calculator">14 * 25</gadget>
<output>350</output>

<result>350</result>