（湖南專版）2020年中考數(shù)學(xué)復(fù)習(xí) 提分專練01 實(shí)數(shù)混合運(yùn)算與代數(shù)式的化簡求值

《（湖南專版）2020年中考數(shù)學(xué)復(fù)習(xí) 提分專練01 實(shí)數(shù)混合運(yùn)算與代數(shù)式的化簡求值》由會(huì)員分享，可在線閱讀，更多相關(guān)《（湖南專版）2020年中考數(shù)學(xué)復(fù)習(xí) 提分專練01 實(shí)數(shù)混合運(yùn)算與代數(shù)式的化簡求值（7頁珍藏版）》請(qǐng)?jiān)谘b配圖網(wǎng)上搜索。

1、提分專練(一)實(shí)數(shù)混合運(yùn)算與代數(shù)式的化簡求值|類型1|實(shí)數(shù)的混合運(yùn)算1.2019南充計(jì)算:(1-)0+|2-3|-12+12-1.2.2019遵義計(jì)算:2sin60+|3-2|+(-1)-1-3-8.3.2019益陽計(jì)算:4sin60+(-2019)0-12-1-|-23|.4.2019齊齊哈爾計(jì)算:13-1+12-6tan60+|2-43|.5.2019濟(jì)寧計(jì)算:6sin60-12+120+|3-2018|.|類型2|整式的化簡求值6.2019南京計(jì)算:(x+y)(x2-xy+y2).7.先化簡,再求值:(x+y)2-y(2x+y),其中x=-2.|類型3|分式的化簡求值8.2019重慶A卷

2、計(jì)算:a+9-4aa-2a2-9a-2.9.化簡:2xyx2-y21x-y+1x+y.10.2019荊門先化簡,再求值:a+ba-b22a-2b3a+3b-4a2a2-b23ab,其中a=3,b=2.11.2019鄂州先化簡x2-2xx2-4x+4-4x-2x-4x2-4,再從-1,2,3,4中選一個(gè)合適的數(shù)作為x的值代入求值.12.2019宜昌已知xy,y=-x+8,求代數(shù)式x2x-y+y2y-x的值.13.2019棗莊先化簡,再求值:x2x2-11x-1+1,其中x為整數(shù)且滿足不等式組x-11,5-2x-2.14.2019菏澤先化簡,再求值:1x-y2yx+y-11y2-x2,其中x=y+

3、2019.【參考答案】1.解:原式=1+3-2-23+2=1-3.2.解:2sin60+|3-2|+(-1)-1-3-8=232+2-3+(-1)-(-2)=3.3.解:4sin60+(-2019)0-12-1-|-23|=432+1-2-23=23+1-2-23=-1.4.解:13-1+12-6tan60+|2-43|=3+23-63+43-2=1.5.解:原式=632-23+1+2018-3=33-23-3+2019=2019.6.解:(x+y)(x2-xy+y2)=x3-x2y+xy2+x2y-xy2+y3=x3+y3.7.解:原式=x2+2xy+y2-2xy-y2=x2.當(dāng)x=-2時(shí),

4、原式=4.8.解:原式=a2-2a+9-4aa-2a-2a2-9=(a-3)2a-2a-2(a+3)(a-3)=a-3a+3.9.解:原式=2xy(x+y)(x-y)2x(x+y)(x-y)=2xy(x+y)(x-y)(x+y)(x-y)2x=y.10.解:原式=2(a+b)3(a-b)-4ab3(a+b)(a-b)=2(a+b)2-4ab3(a+b)(a-b)=2(a2+b2)3(a+b)(a-b).當(dāng)a=3,b=2時(shí),原式=2(3+2)3(3+2)(3-2)=103.11.解:原式=x(x-2)(x-2)2-4x-2x-4x2-4=xx-2-4x-2x-4x2-4=x-4x-2(x-2)(

5、x+2)x-4=x+2.x-20,x-40,x2且x4,當(dāng)x=-1時(shí),原式=-1+2=1.(或當(dāng)x=3時(shí),原式=3+2=5)12.解:原式=x2x-y+y2y-x=x2x-y-y2x-y=x2-y2x-y=(x+y)(x-y)x-y=x+y.當(dāng)xy,y=-x+8時(shí),原式=x+(-x+8)=8.13.解:原式=x2(x+1)(x-1)1+x-1x-1=x2(x+1)(x-1)x-1x=xx+1.解不等式組x-11,5-2x-2,得2x72.因?yàn)閤為整數(shù),所以x=3.代入可得原式=33+1=34.14.解:1x-y2yx+y-11y2-x2=1x-y2y-(x+y)x+y(y+x)(y-x)=-(2y-x-y)=x-y.x=y+2019,原式=y+2019-y=2019.7