The width of a rectangle is 7.5 decimeters, which is 8 decimeters less than the length. What is the perimeter of this rectangle in decimeters?
一个长方形的宽是7.5分米，比长少8分米，求这个长方形的周长是多少分米？
<gadget id="calculator">7.5 + 8 + 7.5</gadget>
<output>23</output>

<gadget id="calculator">23 * 2</gadget>
<output>46</output>

<result>46</result>