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> (1)甲、乙两人同时从A地出发去B地,甲的速度是乙的1.5倍.已知A、B两地相距27千米,甲到达乙地3小时后,乙才到达,求甲、乙两人的速度.(2)甲、乙两人同时从相距9千米的A、B两地-七年级数学
(1)甲、乙两人同时从A地出发去B地,甲的速度是乙的1.5倍.已知A、B两地相距27千米,甲到达乙地3小时后,乙才到达,求甲、乙两人的速度.(2)甲、乙两人同时从相距9千米的A、B两地-七年级数学
题目简介
(1)甲、乙两人同时从A地出发去B地,甲的速度是乙的1.5倍.已知A、B两地相距27千米,甲到达乙地3小时后,乙才到达,求甲、乙两人的速度.(2)甲、乙两人同时从相距9千米的A、B两地-七年级数学
题目详情
(1)甲、乙两人同时从A地出发去B地,甲的速度是乙的1.5倍.已知A、B两地相距27千米,甲到达乙地3小时后,乙才到达,求甲、乙两人的速度.
(2)甲、乙两人同时从相距9千米的A、B两地同时出发,若相向而行,则1小时相遇,若同向而行,乙在甲前面,则甲走了18千米后追上乙,求甲、乙两人的速度.
题型:解答题
难度:偏易
来源:不详
答案
(1)甲为4.5千米/时,乙为3千米/时. (2)甲为6千米/时,乙为3千米/时.
(1)根据甲比乙少用3小时为等量关系列出方程.设乙的速度为x千米/时,列方程得
-
=3,甲为4.5千米/时,乙为3千米/时.
(2)设甲的速度为x千米/时,相向而行,1小时相遇,则(甲速+乙速)×1=9,所以乙速=9-x.又若同向而行,乙在甲前面,则甲走了18千米后追上乙,即甲走18千米所用时间=乙走9千米所用的时间相等,由此可列出方程,得
=
,甲为6千米/时,乙为3千米/时.
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题目简介
(1)甲、乙两人同时从A地出发去B地,甲的速度是乙的1.5倍.已知A、B两地相距27千米,甲到达乙地3小时后,乙才到达,求甲、乙两人的速度.(2)甲、乙两人同时从相距9千米的A、B两地-七年级数学
题目详情
(2)甲、乙两人同时从相距9千米的A、B两地同时出发,若相向而行,则1小时相遇,若同向而行,乙在甲前面,则甲走了18千米后追上乙,求甲、乙两人的速度.
答案
(2)设甲的速度为x千米/时,相向而行,1小时相遇,则(甲速+乙速)×1=9,所以乙速=9-x.又若同向而行,乙在甲前面,则甲走了18千米后追上乙,即甲走18千米所用时间=乙走9千米所用的时间相等,由此可列出方程,得