The perimeter of a rectangle is 70 centimeters, and the length is 5 centimeters more than the width. Now reduce the length and width at the same time, and the area of the reduced rectangle will be half of the area of the original rectangle. If the length is reduced by 5 cm, by how many cm should the width be reduced?
一个长方形的周长是70厘米，长比宽多5厘米，现在要同时减少长和宽，减少以后的长方形面积是原来长方形面积的一半．如果长减少5厘米，宽应该减少多少厘米？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">70 - 10</gadget>
<output>60</output>

<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">5 * 15</gadget>
<output>75</output>

<gadget id="calculator">60 / 4 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">20 * (15/2)</gadget>
<output>150</output>

<gadget id="calculator">300 - 75 - 150</gadget>
<output>75</output>

<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">75 / 15</gadget>
<output>5</output>

<result>5</result>