【正文】
相距20千米,根據(jù)題意得: 解這個(gè)方程組得: 答:上午9點(diǎn)或是上午9點(diǎn)40分兩人相距20千米。(2)情況一:兩人相遇前,還相距20千米,設(shè)小時(shí)后,即時(shí)刻兩人相距20千米,根據(jù)題意得: 解這個(gè)方程組得: 情況二:兩人相遇后,又相距20千米,根據(jù)題意得: 解這個(gè)方程組得: 答:下午1點(diǎn)或是下午3點(diǎn)兩人相距20千米。 coefficient not greater than 。 High efficiency: control 1 hour travel time between any two points within the various groups within the area up to half an hour, 1hour access to the airport, 45min reached the city39。s main traffic hub, external highway for half an hour with the main channels connecting bus hours between any two groups of core areas。 Intensive: 2030 transit share rate of around 35%, 2050 bus sharing rate of 45% per cent. 3rd chapter, Yibin city, traffic situation and General ... city traffic status 1, external transport passenger and cargo traffic in Yibin city, traffic at the present main railway, highway, waterway and air four modes of passenger and freight transport, there