1、初中数学 八年级上册 1/2 期末期末测试测试 答案答案 一一、1.【答案】A 2.【答案】D 3.【答案】D 4.【答案】A 5.【答案】C 6.【答案】D 7.【答案】B 8.【答案】A 9.【答案】B 10.【答案】C 11.【答案】C 12.【答案】B 二二、13.【答案】2x 14.【答案】1abab 15.【答案】90 16.【答案】100100pp 17.【答案】76 18.【答案】6 19.【答案】40 20.【答案】5 三三、21.【答案】(1)原式2222224334(2)(2)abaabababab ab(2)原式()(32)()(32)xyxyxyxy(32)(32)x
2、yxy xyxy(4)(23)xyxy(4)(32)xyyx 初中数学 八年级上册 2/2 22.【答案】解:(1)xyxy,原式(1)11 100yxxyxyxyxyxyxyxy (2)原式2(3)222(3)(3)2(3)(3)3(3)3(3)(3)33232a aaaaaaaaaaaaaaaaaa.3a ,2,3,4a 或5a,则4a 时,原式7.23.【答案】解:(1)(2,0)C,(3,3)D.(2)依题意,得2 36AD ,224BC,3OE,11()(64)31522ABCDSADBCOE梯形.24.【答案】解:CEACCD,ABC和ADE均为等边三角形,ABBCAC,ADAE,
3、60BACEAD,BDACCD,60BADCAD,60CAECAD,BADCAE.又 ADAE,ABAC,ABDACE,BDCE,CEACCD.25.【答案】解:设高铁的速度为x千米/时,则动车的速度为0.4x千米/时,根据题意,得3253251.50.4xx,解得325x.经检验,325x 是分式方程的解.答:高铁的速度是 325 千米/时.26.【答案】(1)证明:ABBC,BE平分ABC,BEAC.CDAB,CFEBFD,ACDDBF.在ADC和FDB中,ACDFBDCDBDCDABDF ,()ADCFDB ASA(2)证明:ADCFDB,ACBF.ABBC,BE平分ABC,CEAE.1122CEACBF.(3)解:ECG为等腰直角三角形.证明:CDBD,CDBD,H是BC边的中点,DHBC,即DH垂直平分BC,GCGB,GBCGCB,BE平分ABC,ACDDBF,ACDCBG,ACDGCB.CDDB,CDDB,45DCB,45ECG,又BEAC,ECG为等腰直角三角形.