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If the speed of a ship sailing downstream is AKM / h and that of a ship sailing upstream is BKM / h (a ＞ B ＞ 0), then the current speed is () A. （a-b）km/hB. (a2-b)km/hC. a+b2km/hD. a-b2km/h
According to the analysis, the flow velocity is a-b2, so D
1 + 5 + 9 +... + (4m-3) = k, try to use the algebraic formula containing K to express 3 + 7 + 11 +... + (4m-1) and explore the algebraic formula containing m to express K
1+5+9+...+(4m-3)=k
3+7+11+...+(4m-1)
=1+2+3+2+9+2+.+4m-3+2
=k+2m
K=3+7+11+...+(4m-1)-2m
Party A and Party B are facing each other in a and B. the speed of Party A is 8000 meters per hour, that of Party B is 6km per hour, and that of Party A is half an hour ahead
B just started. Three hours later, a and B met and asked how far is the distance between a and B
Can we use the equation?
A. B what is the distance between the two places
8*（0.5+3）+6*3=28+18=46km
A. B the distance between the two places is 46 kilometers
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