馨雅资源网https://www.babyxy.cn学魁网http://www.xuekuiw.com丰台区2021年初三学业水平考试统一练习（二）初三数学评分标准及参考答案一、选择题（本题共16分，每小题2分）题号12345678答案DAABDCBC二、填空题（本题共16分，每小题2分）9.10.511.答案不唯一，如：12.13.14.15.16.（1）是；（2）2025三、解答题（本题共68分，第17-22题，每小题5分，第23-26题，每小题6分，第27-28题，每小题7分）17.解：原式，·····························.·································································18.解：解不等式①得：x3，···············································解不等式②得：x8.·················································∴原不等式组的解集为x3.········································19.证明： ∠BAE∠DAC，∴∠BAE+∠EAC∠DAC+∠EAC，即：∠BAC∠DAE.··················································在△BAC和△DAE中，∴△BAC≌△DAE.····················································∴∠C∠E.·····························································20.解：原式，··································.································································· ，∴原式····················································21.（1）如图所示，···············································································（2）AQ,BQ.······················································经过半径的外端并且垂直于这条半径的直...
