HAVING INCREASED SPEED BY 10 Km/h the TRAIN REDUCED TIME SPENT YIM NA PROHOZHDENIYE of the WAY To 720 KM BY 1 HOUR. FIND the INITIAL SPEED of the TRAIN. help to make please the table Speed, Time, Distance

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V, km/h t, h S, km was x 720 became x +10 on 1 h lt; 720,720/x - 720 / (x +10)=1,720 (x +10) - the 720th = x (x +10) the 720th +7200-720kh = x²+10х x²+10х-7200=0 D/4=25+7200=7225=+-85² h1 = - 5 - 85 = - 90 - do not suit the decision h2=-5+85=80 (km/h) - the initial speed of the train
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