2020年4月北京市十八中初三数学综合练习提高卷答案（零模）

第1页（共8页）2019—2020学年度第二学期学年度第二学期初三初三数学数学综合综合练习练习提高卷提高卷答案答案一、一、选择题选择题（本题共（本题共16分，每小题分，每小题2分）分）12345678CDBCCADC二、填空题（本题共二、填空题（本题共16分，每小题分，每小题2分）分）9.4x10.-2，1（答案不唯一）11.45°12.36°13.k=4（答案不唯一）14.③15.17；3016.便携性三三、、解答题（本题共解答题（本题共68分，第分，第17﹣﹣22题，每小题题，每小题5分，第分，第23﹣﹣26题，每小题题，每小题6分，第分，第27，，28题，每小题题，每小题7分）解答应写出文字说明、演算步骤或证明过程．分）解答应写出文字说明、演算步骤或证明过程．17.解:原式=2343-214++−）（…………………4分=35+.…………………5分18.解：解不等式①，342xx−−，…………………1分2x−−，2x.…………………2分解不等式②，23x−≥，…………………3分5x≥.…………………4分不等式①②的解集在数轴上表示如下：∴不等式组的解集为5x≥.…………………5分19．解：(1)22148kkk=−+−+·································································1分()23k=−·················································································2分()230k−，∴方程总有两个实数根．································································3分(2)∵()()2132kkx−−−=，∴11x=−，22xk=−．································································4分∵方程有一个根为正数，∴20k−2k．···············································································5分520