湖南省郴州市2016-2017学年湘教版七年级上数学期末模拟试卷含答案

00%%????x17.118.419.25°20.78或116部分解析:11.)55(?x+)93(??x=014.?????????0211mm17.由已知,当1?x时,743214131213????????baba,得3321??ba.则当1??x时,14)321(43214)1(3)1(213???????????????bababa.18.482121)(212121??????????MCMN19.设???xEBF,则?????xEBFCBE.因为???????90ABFEBFCBE,所以90)15(????xxx,解得??25x.20.因为19?a,97?b,所以19??a,97??b.又因为baba???,则0??ba.所以19?a,97??b或19??a,97??b.当19?a,97??b时,116)97(19?????ba;当19??a,97??b时,78)97(19??????ba.三、解答题。21.(1)解:原式=6)9()21()8(1????????=6941????=6(2)解:原式=21)12()41()12(31)12(5???????????=6345????=12?22.(1)解:去括号,得3163????xx移项,合并同类项得82??x两边都除以2,得4??x(2)解:去分母,得)3(24)1(4xxx?????去括号,得xxx26414?????移项,合并同类项得3??x23.解:∵ba,满足031)1(2????ba,∴2)1(a?与31?b互为相反数.又∵0)1(2??a,031??b,所以0)1(2??a,031??b.∴01??a,031??b,∴1??a,31?b.因此??????????222276645)76()32(25aabaababaabaabab0)1(31)1(3322????????aab.24.解:EG