有分别写有数字9和5的卡片个若干张,甲、乙两人从中分别各取出9张,甲取得写有数字9的卡片张数与乙取得写有数字5的卡片张数恰好相同,甲所取9张卡片的数字比乙所取卡片上的数字和多20.那
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 03:08:23
![有分别写有数字9和5的卡片个若干张,甲、乙两人从中分别各取出9张,甲取得写有数字9的卡片张数与乙取得写有数字5的卡片张数恰好相同,甲所取9张卡片的数字比乙所取卡片上的数字和多20.那](/uploads/image/z/2772232-16-2.jpg?t=%E6%9C%89%E5%88%86%E5%88%AB%E5%86%99%E6%9C%89%E6%95%B0%E5%AD%979%E5%92%8C5%E7%9A%84%E5%8D%A1%E7%89%87%E4%B8%AA%E8%8B%A5%E5%B9%B2%E5%BC%A0%2C%E7%94%B2%E3%80%81%E4%B9%99%E4%B8%A4%E4%BA%BA%E4%BB%8E%E4%B8%AD%E5%88%86%E5%88%AB%E5%90%84%E5%8F%96%E5%87%BA9%E5%BC%A0%2C%E7%94%B2%E5%8F%96%E5%BE%97%E5%86%99%E6%9C%89%E6%95%B0%E5%AD%979%E7%9A%84%E5%8D%A1%E7%89%87%E5%BC%A0%E6%95%B0%E4%B8%8E%E4%B9%99%E5%8F%96%E5%BE%97%E5%86%99%E6%9C%89%E6%95%B0%E5%AD%975%E7%9A%84%E5%8D%A1%E7%89%87%E5%BC%A0%E6%95%B0%E6%81%B0%E5%A5%BD%E7%9B%B8%E5%90%8C%2C%E7%94%B2%E6%89%80%E5%8F%969%E5%BC%A0%E5%8D%A1%E7%89%87%E7%9A%84%E6%95%B0%E5%AD%97%E6%AF%94%E4%B9%99%E6%89%80%E5%8F%96%E5%8D%A1%E7%89%87%E4%B8%8A%E7%9A%84%E6%95%B0%E5%AD%97%E5%92%8C%E5%A4%9A20.%E9%82%A3)
有分别写有数字9和5的卡片个若干张,甲、乙两人从中分别各取出9张,甲取得写有数字9的卡片张数与乙取得写有数字5的卡片张数恰好相同,甲所取9张卡片的数字比乙所取卡片上的数字和多20.那
有分别写有数字9和5的卡片个若干张,甲、乙两人从中分别各取出9张,
甲取得写有数字9的卡片张数与乙取得写有数字5的卡片张数恰好相同,甲所取9张卡片的数字比乙所取卡片上的数字和多20.那么乙所取9张卡片上的数字之和是多少
有分别写有数字9和5的卡片个若干张,甲、乙两人从中分别各取出9张,甲取得写有数字9的卡片张数与乙取得写有数字5的卡片张数恰好相同,甲所取9张卡片的数字比乙所取卡片上的数字和多20.那
设甲取得数字9的卡片张数是X 9X+5*(9-X)-20=5X+9*(9-X)解得X=7
那么乙的数字和是5*7+9*2=53
53
设甲取到x张9,则:
9x+5(9-x)=5x+9(9-x)+20
解得:x=7
所以乙取得数之和为5x+9(9-x)=53
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