深圳市2025年中考模拟考试数学学科 参考答案与评分标准 一、选择题 题号 1 2 3 4 5 6 7 8 答案 B A D D C A C B 二、填空题 题号 9 10 11 12 13 答案 13 70 三、解答题 14. 解: ··········································4分(一个知识点1分) ······························································5分 ·················································································6分 15. 解: (1); ·····················································2分 (2)∵,········································3分 ∴, ·····················································4分 ∴(a﹣1)2=2,即a2﹣2a+1=2, ∴a2﹣2a=1, ·····················································5分 ∴原式=4(a2﹣2a)﹣2=4﹣2=2. ·················································7分 16. 任务1:m=9,n=8 ······································································2分 任务2: A的综合成绩为: ·······························3分 B的综合成绩为: ·······························4分 C的综合成绩为: ·······························5分 ∵86.2>85.8 ∴B机器人的综合成绩最高. ·······················································6分 任务3: ①选择B机器人,因为B机器人得运动能力测试能力比较高. ②选择B机器人,因为B机器人运动能力成绩得方差比较小,说明B机器人得运动能力比较稳定. ③选择A机器人,因为A机器人运动能力测试得众数是9和10,说明较多专业测试员认为A机器人得运动能力很好. (答案不唯一,言之有理即可) ·······················································8分 17. 解: (1)设“哪吒”、“敖丙”两种书签每张的进价分别是x、y元···········1分 由题意知: ······························3分 解得 ······························4分 答:“哪吒”、“敖丙”两种书签每张的进价分别是9、8元. ················5分(2)设购进“哪吒”书签m张,“敖丙”书签(90-x)张 由题意知: 解得 ······························6分 设这批书签全部售出后获利W元,则 ······························7分 ∵2>0, ∴W随m得增大而增大, ∴当m=40时,90-m=50,W有最大值, . 答:当购进“哪吒”书签40张,“敖丙”书签50张时,获得最大利润,最大利润是440元. ······························9分 18.解: 方法1: (1)∵DE⊥AC,DF⊥BC, ∴∠CED=∠CFD=90° ∵∠ACB=90° ∴四边形CEDF是矩形 ····· ... ...
~~ 您好,已阅读到文档的结尾了 ~~