An engineering team builds a road with a length of 4200m, and repairs 150m every day for the first 8 days. If the next 300m is built every day, how many days will it take to complete the road?
一个工程队修筑一条长4200m的路，前8天每天修150m，如果接下来每天修300m，修完这条路一共要用多少天？
<gadget id="calculator">150 * 8</gadget>
<output>1_200</output>

<gadget id="calculator">4_200 - 1_200</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 / 300</gadget>
<output>10</output>

<gadget id="calculator">10 + 8</gadget>
<output>18</output>

<result>18</result>