A highway has been built for 5.4 kilometers, and the rest is 1.25 kilometers less than 2.1 times the repaired one. How many kilometers are left to be repaired?
修一条公路，已经修了5.4千米，剩下的比修好的2.1倍少1.25千米，请问剩下多少千米没修？
<gadget id="calculator">5.4 * 2.1</gadget>
<output>11.34</output>

<gadget id="calculator">11.34 - 1.25</gadget>
<output>10.09</output>

<result>10.09</result>