Xiaomao climbed the mountain, traveling 2.4 kilometers per hour when going up the mountain, and 3 kilometers per hour when going down the mountain. It took him 4.5 hours from the bottom of the mountain to the top of the mountain, and then down the same road from the top of the mountain. How many kilometers is the distance from the bottom of the mountain to the top of the mountain? Solve the equation.
小毛登山，上山时每小时行2.4千米，下山时每小时行3千米，他从山下到山顶，再从山顶原路下山，共用4.5小时．求从山下到山顶的路程有多少千米？用方程解．
<gadget id="calculator">4.5 * 3</gadget>
<output>13.5</output>

<gadget id="calculator">2.4 + 3</gadget>
<output>5.4</output>

<gadget id="calculator">13.5 / 5.4</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 * 2.4</gadget>
<output>6</output>

<result>6</result>