在平面直角坐标系中,点A的坐标为(3, -2),点B的坐标为(-1, 4)。某学生计算线段AB的长度时,使用了距离公式。请问线段AB的长度是多少?
💡 提示:点击下方 "查看答案" 查看解析,或 "提交答案" 后自动显示结果
首先计算前3天总共清理的垃圾袋数量:3天 × 8袋/天 = 24袋。后2天共清理18袋,因此5天总共清理了24 + 18 = 42袋。平均每天清理的数量为总袋数除以天数,即42 ÷ 5 = 8.4袋。本题考查的是数据的收集、整理与描述中的平均数计算,属于简单难度的应用题。
🏆
练习完成!
恭喜您完成了本次练习,继续加油提升!
💡 学习建议:您在一元一次方程的应用方面掌握良好,但仍有提升空间。建议重点复习方程求解步骤和实际应用问题。
[{"id":578,"content":"26","type":"选择题","subject":"数学","grade":"初一","stage":"小学","difficulty":"简单","answer":"待完善","explanation":"解析待完善","options":[]},{"id":2455,"content":"在一次班级数学测验中,某学生记录了5名同学的数学成绩分别为85分、90分、78分、92分和_分,已知这5个成绩的平均数是86分,则第五个成绩是___分。","type":"填空题","subject":"数学","grade":"八年级","stage":"初中","difficulty":"中等","answer":"85","explanation":"设第五个成绩为x,根据平均数公式:(85+90+78+92+x)÷5=86,解得x=85。","options":[]},{"id":2292,"content":"某学生测量了一块直角三角形纸片的两条直角边,分别为5 cm和12 cm。若要用一根细线沿着纸片的边缘完整绕一圈,所需细线的最短长度是多少?","type":"选择题","subject":"数学","grade":"八年级","stage":"初中","difficulty":"简单","answer":"A","explanation":"题目要求计算直角三角形纸片的周长,即三条边之和。已知两条直角边分别为5 cm和12 cm,首先利用勾股定理求斜边:斜边 = √(5² + 12²) = √(25 + 144) = √169 = 13 cm。因此,周长为 5 + 12 + 13 = 30 cm。所需细线的最短长度即为周长,故正确答案为A。","options":[{"id":"A","content":"30 cm"},{"id":"B","content":"25 cm"},{"id":"C","content":"17 cm"},{"id":"D","content":"13 cm"}]},{"id":447,"content":"某学生调查了班级同学每天用于课外阅读的时间(单位:分钟),并将数据整理如下表:\n\n| 阅读时间(分钟) | 人数 |\n|------------------|------|\n| 0~20 | 5 |\n| 20~40 | 8 |\n| 40~60 | 12 |\n| 60~80 | 10 |\n| 80~100 | 5 |\n\n则该班级学生每天课外阅读时间的众数所在的区间是?","type":"选择题","subject":"数学","grade":"初一","stage":"初中","difficulty":"简单","answer":"C","explanation":"众数是指一组数据中出现次数最多的数据。在本题中,虽然无法知道每个具体数值,但可以确定哪个区间的人数最多,即频数最高的区间就是众数所在的区间。从表中可以看出,阅读时间在40~60分钟的人数最多,为12人,因此众数所在的区间是40~60分钟。","options":[{"id":"A","content":"0~20分钟"},{"id":"B","content":"20~40分钟"},{"id":"C","content":"40~60分钟"},{"id":"D","content":"60~80分钟"}]},{"id":2201,"content":"某学生在数轴上从原点出发,先向右移动5个单位长度,再向左移动8个单位长度。此时该学生所在位置所表示的数是___。","type":"选择题","subject":"数学","grade":"七年级","stage":"初中","difficulty":"简单","answer":"B","explanation":"从原点出发向右移动5个单位,表示+5;再向左移动8个单位,表示-8。最终位置为5 + (-8) = -3,因此该学生所在位置表示的数是-3。","options":[{"id":"A","content":"3"},{"id":"B","content":"-3"},{"id":"C","content":"13"},{"id":"D","content":"-13"}]},{"id":2450,"content":"在一次函数 y = kx + b 的图像中,已知该函数与 x 轴交于点 (4, 0),与 y 轴交于点 (0, -6),则 k 的值为___。","type":"填空题","subject":"数学","grade":"八年级","stage":"初中","difficulty":"中等","answer":"3\/2","explanation":"由 y 轴交点得 b = -6,代入 x 轴交点 (4, 0) 得 0 = 4k - 6,解得 k = 3\/2。","options":[]},{"id":193,"content":"小明买了3支铅笔和2本笔记本,共花费18元。已知每支铅笔2元,那么每本笔记本多少钱?","type":"选择题","subject":"数学","grade":"初一","stage":"小学","difficulty":"简单","answer":"A","explanation":"首先计算3支铅笔的总价:3 × 2 = 6(元)。小明一共花了18元,因此2本笔记本的总价为:18 - 6 = 12(元)。那么每本笔记本的价格为:12 ÷ 2 = 6(元)。所以正确答案是A。","options":[{"id":"A","content":"6元"},{"id":"B","content":"5元"},{"id":"C","content":"4元"},{"id":"D","content":"3元"}]},{"id":434,"content":"12人","type":"选择题","subject":"数学","grade":"初一","stage":"小学","difficulty":"简单","answer":"待完善","explanation":"解析待完善","options":[]},{"id":452,"content":"某班级为了了解学生最喜欢的课外活动,随机抽取了50名学生进行调查,并将结果绘制成扇形统计图。其中,喜欢阅读的学生所占的圆心角为72度。那么,喜欢阅读的学生人数是多少?","type":"选择题","subject":"数学","grade":"初一","stage":"初中","difficulty":"简单","answer":"A","explanation":"扇形统计图中,每个部分的圆心角占整个圆(360度)的比例等于该部分人数占总人数的比例。已知喜欢阅读的学生对应的圆心角是72度,总调查人数为50人。计算方法是:(72 ÷ 360) × 50 = 0.2 × 50 = 10。因此,喜欢阅读的学生有10人。","options":[{"id":"A","content":"10人"},{"id":"B","content":"12人"},{"id":"C","content":"15人"},{"id":"D","content":"20人"}]},{"id":323,"content":"中位数是152,众数是148","type":"选择题","subject":"数学","grade":"初一","stage":"小学","difficulty":"简单","answer":"答案待完善","explanation":"解析待完善","options":[]}]