The ratio of length to 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 will increase by 100 cm2. So what is the area of the original cuboid?
一个长方形长和宽的比是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．那么原来长方体的面积是多少．
<gadget id="calculator">14 * 25</gadget>
<output>350</output>

<result>350</result>