中考数学考点集训分类训练3 分式(含答案)

分类训练3分式命题点1分式有意义的条件1(2022黄冈)若分式2x-1有意义,则x的取值范围是命题点2分式值为0的条件2(2022广西北部湾经济区)当x=时,分式2xx命题点3分式的化简3(2022山西)化简1a-3-6a2-9A.1a+3 B.a-3 C.a+34(2022威海)试卷上一个正确的式子(1a+b+1a-b)÷★=2aA.aa-b B.a-b5(2022苏州)化简x2x-2-26(2022自贡)化简:a-3a2+4a+4·7(2022河南)化简:x2-1x÷(1-8(2022天门)化简:(m2-9m2-6m9(2022泰安)化简:(a-2-4a-2)÷命题点4分式的化简求值角度1已知字母的值10(2022株洲)先化简,再求值:(1+1x+1)·x+1x2+411(2022达州)化简求值:a-1a2-2a+1÷(a2+aa角度2结合实数的运算12(2022滨州)先化简,再求值:(a+1-3a-1)÷a2+4a+4a-1,其中a=tan45°+(13(2022荆州)先化简,再求值:(aa2-b2-1a+b)÷ba2-2ab+b2,其中角度3结合方程14(2022南充)已知a>b>0,且a2+b2=3ab,则(1a+1b)2÷(1a2-1b2A.5 B.-5C.55 D.-15(2022宜昌)求代数式3x+2yx2-y2+角度4结合不等式组16(2022广元)先化简,再求值:2x2+x÷(1-x-1x2角度5自选值代入17(2022邵阳)先化简,再从-1,0,1,3中选择一个合适的x值代入求值.(1x+1+1x2分类训练3分式1.x≠12.03.A【解析】原式=a+3(a-3)(a+3)-4.A【解析】2a+b≠0,(1a+b+1a-b)÷25.x【解析】原式=x2-2x6.aa+2【解析】原式=a-3(a+2)2·(a+2)(7.【参考答案】原式=(x+1)(=x+1.8.【参考答案】原式=[(m+3)(m-3)=(m+3m-3-=mm-3=1m9.【参考答案】原式=(a-2=a2-4=a(a=a(a+2)=a2+2a.10.【参考答案】原式=(x+1x+1+=x+2x=1x∵x=4,∴原式=14+2=111.【参考答案】原式=a-1(=a-1(=1a当a=3-1时,原式=13-1+1=12.【参考答案】原式=(a2-1a-1-=a2-4=(a+2)(=a-2∵a=tan45°+(12)-1-π0=1+2-1=∴原式=2-22+2=013.【参考答案】原式=[a(a+b=a(a+b)(a=a2-=b=a-∵a=(13)-1=3,b=(-2022)0=∴原式=3-13+1=114.B【解析】原式=(a+b)2a2b2÷(-a2-b2a2b2)=-(a+b)2a2b2·a2b2(a+b)(a-b)=-a+ba-b.∵a2+b2=3ab,∴a2+b2+2ab=3ab+2ab,a2+b2-215.【参考答案】原式=3x+2yx2-=2x当x=2+y时,原式=22=116.【参考答案】原式=2x(=2x(=2x解2(x-1)<x+1,得x<3,解5x+3≥2x,得x≥-1,故不等式组的解集为-1≤x<3,其整数解为-1,0,1,2.∵当x=-1,0