2021.1-9S2-E大兴初三数学2021.1期末答案

初三数学参考答案及评分标准第1页（共7页）大兴区2020~2021学年度第一学期期末检测初三数学参考答案及评分标准一、选择题（本题共24分，每小题3分）题号12345678答案CABDBCDB二、填空题（本题共24分，每小题3分）9.0m；10.=；11.（2，-4）；12.2；13.43；14.答案不唯一，例如：yx；15.①②③；16.1<m<5.三、解答题（本题共52分，第17-21题，每小题5分，第22题6分，第23-25题,每小题7分）解答应写出文字说明、演算步骤或证明过程.17.解:2221312--原式········································4分22131--223-··················································5分18.解：（1）∵抛物线2+yxbxc经过点（1，-4），（0，-3），∴1+43bcc.··················································2分解得-2-3bc.∴2-2-3yxx．················································3分（2）令y=0,∴2-2-30xx.解得:121,3xx.∴抛物线与x轴的交点坐标是（-1,0），（3,0）.······················5分