
2025年鞍山市初中九年级第一次质量调查 2025年鞍山市初中九年级第一次质量调查 数学参考答案及评分标准 一、 选择题:(每题 2分,共 20分) 题号 1 2 3 4 5 6 7 8 9 10 答案 B C C D A B D C C A 二、填空题:(每题 3 分,共 15 分) 11. 12. 答案不唯一(例如:DB=EC, AB=AC, ∠DAB=∠EAC 等) 3 13 13. 14. x1 x2 1或x1 x2 1 15. 2 3 三、解答题:(本题共 75分) 16. 计算:(共 10分) 解: (1)原式= 2 3 ( 2) 2 3 ············································ (3 分) =3 3 4 ··························································· (5 分) m2 4 5 2(m 2) (2)原式=( ).( ) ······························ (2 分) m 2 m 2 3 m (m 3)(m 3) 2(m 2) = . ·································· (3 分) m 2 (m 3) = (2 m 3) ······················································ (4 分) = 2m 6 ························································ (5 分) 17. (8分) (1)解:设该校共有 x 名学生参加活动 x 30 x 根据题意 1 ·············································· (3 分) 60 45 解得 x 270 ············································· (5 分) 答:该校共有 270 名学生参加活动. ······································ (6 分) (2)租 60 座客车 3 辆, 45 座客车 2 辆最为合算。 ······················· (8 分) 18.(8分) (1)解:90 45% 200(人) ∴发放调查问卷总数是 200 ··········································· (1分) 炸串:200 30% 60 (人),作图 ····································· (3分) 春联:200 15% 30 (人),作图 ····································· (5分) 人数 100 90 80 6060 30 40 20 16 4 0 饮品 炸串 春联 手工饰品 手机壳 产品 2 (2)饮品 x 40% 0.4 0.3 45% 0.3 0.355 10 4 x 50% 0.4 0.3 30% 0.3 10 0.41 ······························································· (7分) ∵0.41>0.35 ∴大学生应选择炸串. ·················································· (8分) 19.(8分) 解:由题意 ∠MNA=90° MN 在 Rt△MAN 中 tan MAN AN MN MN ∴ AN ····················································· (3分) tan35 0.7 在 Rt△MBN 中 MN tan MBN NB MN MN ∴ NB ··················································· (6分) tan25 0.47 ∵ NB NA 10 MN MN ∴ 10 0.47 0.7 1 1 ∴MN 10 ( ) 0.47 0.7 ∴MN 14.3(米) ··························································· (7分) 答: ... ...
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