A and B walk a certain distance together, A walks 4.5 kilometers per hour, B travels 1.5 kilometers less than A per hour, and A takes 2.5 hours less than B to complete the distance. Find the length of the distance in kilometers ．
甲、乙两人同走一段路，甲每小时走4.5千米，乙每小时比甲少走1.5千米，甲比乙少用2.5小时走完这段路，求这段路长多少千米．
<gadget id="calculator">2.5 * 4.5 * 4.5</gadget>
<output>50.625</output>

<gadget id="calculator">2.5 * 1.5 * 4.5</gadget>
<output>16.875</output>

<gadget id="calculator">50.625 - 16.875</gadget>
<output>33.75</output>

<gadget id="calculator">1.5 - 4.5</gadget>
<output>-3</output>

<gadget id="calculator">4.5 + (-3)</gadget>
<output>1.5</output>

<gadget id="calculator">33.75 / 1.5</gadget>
<output>22.5</output>

<result>22.5</result>