南方大地震为四川人民带来巨大灾难，学校也受到了严重破坏，为了让灾区的孩子们能尽快在一个舒适、优美的环境里读书．某对口支援单位承担了重建学校的任务，为了美化校园．计划在一块长19米．宽15米的长方形空地上新建一块长方形花圃，并要求花圃四周空地的宽度一样．计划新建花圃的面积为77米2，问花圃的长和宽是多少米？
设四周空地的宽度为x米，
依题：（19-2x）（15-2x）=77，
即：x2-17x+52=0
解之，x1=4，x2=13（舍去），
花圃的长为19-2×4=11（米）
宽为15-2×4=7（米）．
答：矩形花圃的长为11米，宽为7米．
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| Sports in America In many parts of the world, there are four seasons: spring, summer, fall and winter. In the USA, there are only three: football, basketball and baseball. If you want to know 1 , just have a look at what people are playing. Sports are an important part of American culture. Throughout their school 2 , Americans learn to play many sports. All students take P.E. classes in school. Some try out for the school teams, 3 others join school sports leagues. For many people in the USA, sports are not just 4 . They're almost a religion (宗教). 5 sports fans buy expensive tickets to watch their favorite teams and athletes 6 in person. Other fans watch games at home, glued to their TV sets. The most devoted (投入的) sports fans 7 a game. | |||
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