浙江省中考数学数与式课时训练03分式练习（新版）浙教版.docx

课时训练(三)分式夯实基础1.2018绵阳 等式x-3x+1=x-3x+1成立的x的取值范围在数轴上可表示为()图K3-12.2017宜昌 计算(x+y)2-(x-y)24xy的结果为()A.1B.12C.14D.03.2018南充 已知1x-1y=3,则代数式2x+3xy-2yx-xy-y的值是()A.-72B.-112 C.92D.344.下列运算结果为x-1的是()A.1-1xB.x2-1xxx+1C.x+1x1x-1D.x2+2x+1x+15.2016衢州 当x=6时,分式51-x的值等于.6.观察下列一组数:32,1,710,917,1126,它们是按一定规律排列的,那么这组数的第n个数是(n为正整数).7.2017包头 化简:a2-1a2(1a -1)a=.8.某班a名同学参加植树活动,其中男生b名(ba),若只由男生完成,每人需植树15棵,若只由女生完成,则每人需植树棵.9.观察规律并填空:1-122=1232=34;(1-122)(1-132)=12322343=1243=23;(1-122)(1-132)(1-142)=123223433454=1254=58;(1-122)(1-132)(1-142)(1-152)=1232234334544565=1265=35;(1-122)(1-132)(1-142)(1-1n2)=(用含n的代数式表示,n是正整数,且n2).10.(1)化简:4a+4b5ab15a2ba2-b2.(2)2018盐城 先化简,再求值:(1- 1x+1)xx2-1,其中x=2+1.11.2018曲靖 先化简,再求值(1a-b-ba2-b2)a2-aba2-2ab+b2,其中a,b满足a+b-12=0.12.已知A=x2+2x+1x2-1-xx-1.(1)化简A;(2)当x满足不等式组x-1鈮?,x-30,解得x3.故选B.2.A解析 根据整式的运算法则及分式的基本性质化简,原式=x2+y2+2xy-x2-y2+2xy4xy=4xy4xy=1.3.D解析 1x-1y=3,y-x=3xy,x-y=-3xy,原式=2(x-y)+3xy(x-y)-xy=-6xy+3xy-3xy-xy=-3xy-4xy=34.4.B5.-16.2n+1n2+17.-a-18.15ba-b9.n+12n10.解:(1)4a+4b5ab15a2ba2-b2=4(a+b)5ab15a2b(a+b)(a-b)=12aa-b.(2)原式=x+1-1x+1x2-1x=xx+1(x+1)(x-1)x=x-1.当x=2+1时,原式=2+1-1=2.11.解:( 1a-b-ba2-b2)a2-aba2-2ab+b2=a+b(a+b)(a-b)-b(a+b)(a-b)(a-b)2a(a-b)=a+b-b(a+b)(a-b)a-ba=aa+b1a=1a+b.由于a,b满足a+b-12=0,所以a+b=12,因此原式化简后的式子:1a+b=112=2.12.解:(1)A=(x+1)2(x+1)(x-1)-xx-1=x+1x-1-xx-1=x+1-xx-1=1x-1.(2)解不等式组,得1x3.x为整数,x=1或x=2.A=1x-1,x1.当x=2时,A=1x-1=12-1=1.13.解:原式=a(a+2)(a-2)a+2a(a-3)+1a-2=1(a-2)(a-3)+a-3(a-2)(a-3)=a-2(a-2)(a-3)=1a-3.a与2,3构成ABC的三边长,3-2a3+2,即1a-3,不等式组的解集为-3x1.(3xx-1-xx+1)xx2-1=3x(x+1)-x(x-1)(x-1)(x+1)x2-1x=3x(x+1)-x(x-1)(x-1)(x+1)(x-1)(x+1)x=3(x+1)-(x-1)=3x+3-x+1=2x+4.x0,x1,当x取-2时,原式=2(-2)+4=0.15.解:(1)f(2)=2222+1=45,f(-3)=2-32-3+1=19.(2)猜