An engineering team builds a 15.8-kilometer-long highway. It builds 5 kilometers in the first week, and builds 0.7 kilometers more in the second week than in the first week. How many kilometers will it take to complete the construction?
一个工程队修筑一条15.8千米长的公路，第一周修了5千米，第二周比第一周多修0.7千米，还要修多少千米才能修完？
<gadget id="calculator">5 + 0.7</gadget>
<output>5.7</output>

<gadget id="calculator">15.8 - 5 - 5.7</gadget>
<output>5.1</output>

<result>5.1</result>