The master worker wants to build a road, and has already built 52.4 kilometers, and the rest is 2.8 kilometers more than 1.5 times the repaired one. How many kilometers are left to be repaired?
工人师傅要修一条公路，已经修了52.4千米，剩下的比修好的1.5倍多2.8千米，还剩多少千米没有修？
<gadget id="calculator">52.4 * 1.5</gadget>
<output>78.6</output>

<gadget id="calculator">78.6 + 2.8</gadget>
<output>81.4</output>

<result>81.4</result>