初一七年級(jí)化簡(jiǎn)求值100題

初一七年級(jí)化簡(jiǎn)求值100題1、-9(x-2)-y(x-5)(1)化簡(jiǎn)整個(gè)式子。(2)當(dāng)x=5時(shí)，求y的解。2、5(9+a)xb-5(5+b)xa(1)化簡(jiǎn)整個(gè)式子。(2)當(dāng)a=5/7時(shí)，求式子的值。3、62g+62(g+b)-b(1)化簡(jiǎn)整個(gè)式子。(2)當(dāng)g=5/7時(shí)，求b的解。4、3(x+y)-5(4+x)+2y化簡(jiǎn)整個(gè)式子。5、僅+y)(x-y)化簡(jiǎn)整個(gè)式子。6、2ab+axa-b化簡(jiǎn)整個(gè)式子。7、5.6x+4(x+y)-y化簡(jiǎn)整個(gè)式子。8、6.4(x+2.9)-y+2(x-y)化簡(jiǎn)整個(gè)式子。9、(2.5+x)(5.2+y)化簡(jiǎn)整個(gè)式子。3ab-4ab+8ab-7ab+ab=

7x-(5x-5y)-y=.23a3bc2-15ab2c+8abc-24a3bc2-8abc=.-7x2+6x+13x2-4x-5x2=.2y+(-2y+5)-(3y+2)=.(2x2-3xy+4y2)+(x2+2xy-3y2)=..2x+2y-[3x-2(x-y)]=..5-(1-x)-1-(x-1)=..()+(4xy+7x2-y2)=10x2-xy..(4xy2-2x2y)-()=x3-2x2y+4xy2+y3.20.2a-(3a-2b+2)+(3a-4b-1)=..已知A=x3-2x2+x-4,B=2x3-5x+3,計(jì)算A+B=..已知A=x3-2x2+x-4,B=2x3-5x+3,計(jì)算A-B=..若a=-0.2,b=0.5,代數(shù)式-(|a2b|-|ab2|)的值為..2x-(x+3y)-(-x-y)-(x-y)=..一個(gè)多項(xiàng)式減去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么這個(gè)多項(xiàng)式等于*26.-(2x2-y2)-[2y2-(x2+2xy)]=.27.若-3a3b2與5ax-1by+2是同類項(xiàng)，則x=,y=.28.(-y+6+3y4-y3)-(2y2-3y3+y4-7)=.29.化簡(jiǎn)代數(shù)式4x2-[7x2-5x-3(1-2x+x2)]的結(jié)果是.30.2a-b2+c-d3=2a+()-d3=2a-d3-()=c-().

.3a-(2a-3b)+3(a-2b)-b=..化簡(jiǎn)代數(shù)式x-[y-2x-(x+y)]等于..[5a2+()a-7]+[()a2-4a+()]=a2+2a+1..3x-[y-(2x+y)]=..化簡(jiǎn)|1-x+y|-|x-y|(其中x<0,y>0)等于.已知x<yx+y-|x-y|=..已知x<0,y<0,化簡(jiǎn)|x+y|-|5-x-y|=..4a2n-an-(3an-2a2n)=..若一個(gè)多項(xiàng)式加上-3x2y+2x2-3xy-4得2x2y+3xy2-x2+2xy,則這個(gè)多項(xiàng)式為..-5xm-xm-(-7xm)+(-3xm)=..當(dāng)a=-1,b=-2時(shí)，[a-(b-c)]-[-b-(-c-a)]=..-6x2-7x2+15x2-2x2=..當(dāng)a=-1,b=1,c=-1時(shí)，-[b-2(-5a)]-(-3b+5c)=.44.-2(3x+z)-(-6x)+(-5y+3z)=.45.-5an-an+1-(-7an+1)+(-3an)=.46.3a-(2a-4b-6c)+3(-2c+2b)=.

48.9a2+[7a2-2a-(-a2+3a)]=..當(dāng)2y-x=5時(shí)，5(x-2y)2-3(-x+2y)-100=(二)選擇.下列各式中計(jì)算結(jié)果為-7x-5x2+6x3的是[]3x-(5x2+6x3-10x)；3x-(5x2+6x3+10x)；3x-(5x2-6x3+10x)；3x-(5x2-6x3-10x)..把(-x-y)+3(x+y)-5(x+y)合并同類項(xiàng)得[](x-y)-2(x+y)；-3(x+y)；(-x-y)-2(x+y)；3(x+y)..2a-[3b-5a-(2a-7b)]等于[]-7a+10b；5a+4b；-a-4b；9a-10b..減去-3m等于5m2-3m-5的代數(shù)式是[]5(m2-1)；5m2-6m-5；

5(m2+1)；-(5m2+6m-5).55.將多項(xiàng)式2ab-9a2-5ab-4a2中的同類項(xiàng)分別結(jié)合在一起，應(yīng)為[](9a2-4a2)+(-2ab-5ab)；(9a2+4a2)-(2ab-5ab)；(9a2-4a2)-(2ab+5ab)；(9a2-4a2)+(2ab-5ab).56.當(dāng)a=2,b=1時(shí)，-a2b+3ba2-(-2a2b)等于[]20；24；0；16.57.若A和B均為五次多項(xiàng)式，則A-B一定是[]A.十次多項(xiàng)式；B.零次多項(xiàng)式；C.次數(shù)不高于五次的多項(xiàng)式；D.次數(shù)低于五次的多項(xiàng)式.58.-{[-(x+y)]}+{-[(x+y)]}等于[]0；-2y；x+y；

-2x-2y.59.若A=3x2-5x+2,B=3x2-5x+6,則A與B的大小是A>B；A=B；A<B；D.無(wú)法確定.60.當(dāng)m=-1時(shí)，-2m2-卜4m2+tm2)]等于[]-7；3；1；2.61.當(dāng)m=2,n=1時(shí)，多項(xiàng)式-m-[-(2m-3n)]+[<-3m)-4n]等于[]1；9；3；5.4x2y-5xy2的結(jié)果應(yīng)為[]-x2y；-1；-x2y2；D.以上答案都不對(duì).

(三)化簡(jiǎn)2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2).4x-2(x-3)-3[x-3(4-2x)+8].5m2n+(-2m2n)+2mn2-(+m2n).4(x-y+z)-2(x+y-z)-3(-x-y-z).2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).(4x2-8x+5)-(x3+3x2-6x+2).(-x2+4+3x4-x3)-(x2+2x-x4-5).若A=5a2-2ab+3b2,B=-2b2+3ab-a2,^A+B.已知A=3a2-5a-12,B=2a2+3a-4,求2(A-B).(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).-{2a2b-[3abc-(4ab2-a2b)]}.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).75.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).76.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).77.(4a-2b-c)-5a-[8b-2c-(a+b)].78.(2m-3n)-(3m-2n)+(5n+m).79.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).80.xy-(2xy-3z)+(3xy-4z)..(-3x3+2x2-5x+1)-(5-6x-x2+x3).

.3x-(2x-4y-6x)+3(-2z+2y)..2m-{-3n+[-4m-(3m-n)]}.(四)將下列各式先化簡(jiǎn)，再求值.已知a+b=2,a-b=-1,求3(a+b)2(a-b)2-5(a+b)2x(a-b)2的值..已知A=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,求(A-B)+C..求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2..已知|x+1|+(y-2)2=0,求代數(shù)式5(2x-y)-3(x-4y)的值..當(dāng)P=a2+2ab+b2,Q=a2-2ab-b2時(shí)，求P-[Q-2P-(P-Q)]..求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值，其中x=-3..當(dāng)x=-2,y=-1,z=3時(shí)，求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值..已知A=x3-5x2,B=x2-6x+3,求A-3(-2B).(五)綜合練習(xí).去括號(hào)：{-[-(a+b)]}-{-[-(a-b)]}..去括號(hào)：-[-(-x)-y]-[+(-y)-(+x)]..已知A=x3+6x-9,B=-x3-2x2+4x-6,計(jì)算2A-3B,并把結(jié)果放在前面帶“-”號(hào)的括號(hào)內(nèi)..計(jì)算下式，并把結(jié)果放在前面帶“-”號(hào)的括號(hào)內(nèi)：(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y).

.去括號(hào)、合并同類項(xiàng)，將結(jié)果按x的升冪排列，并把后三項(xiàng)放在帶有“-”號(hào)的括號(hào)內(nèi)：.不改變下式的值，將其中各括號(hào)前的符號(hào)都變成相反的符號(hào)：(x3+3x2)-(3x2y-7xy)+(2y3-3y2)..用豎式計(jì)算(-x+5+2x4-6x3)-(3x4+2x2-3x3-7)..已知A=11x3+8x2-6x+2,B=7x3-x2+x+3,^2(3A-2B)..已知A=x3-5x2,B=x3-11x+6,C=4x-3,求⑴A-B-C；⑵(A-B-C)-(A-B+C)..已知A=3x2-4x3,B=x3-5x2+2,計(jì)算(1)A+B；(2)B-A..已知x<-4,化簡(jiǎn)|-x|+|x+4|-|x-4|..求兩代數(shù)式-1.56a+3.2a3-0.47,2.27a3-0.02a2+4.03a+0.53的差與6-0.15a+3.24a2+5.07a3的和..已知僅-3)2+|丫+1|+22=0,求x2-2xy-5x2+12xz+3xy-z2-8xz-2x2的值..在括號(hào)內(nèi)填上適當(dāng)?shù)捻?xiàng)：(1)x2-xy+y-1=x2-()；(2)[()+6x-7]-[4x2+()-()]=x2-2x+1.

.計(jì)算4x2-3[x+4(1-x)-x2卜2(4x2-1)的值..化簡(jiǎn):2x2-{-3x-[4x2-(3x2-x)+(x-x2)]}..化簡(jiǎn):-(7x-y-2z)-{[4x-(x-y-z)-3x+z]-x}..計(jì)算:(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a)..化簡(jiǎn)：a3-(a2-a)+(a2-a+1)-(1-a4+a3)..將x2-8x+2x3-13x2-2x-2x3+3先合并同類項(xiàng)，再求值，其中x=-4..把多項(xiàng)式4x2y-2xy2+4xy+6-x2y2+x3-y2的三次項(xiàng)放在前面帶有“-”號(hào)的括號(hào)內(nèi)，二次項(xiàng)放在前面帶有“+”號(hào)的括號(hào)內(nèi)，四次項(xiàng)和常數(shù)項(xiàng)放在前面帶有“-”號(hào)的括號(hào)內(nèi)..合并同類項(xiàng):7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y..合并同類項(xiàng)：5m2n+5mn2-mn+3m2n-6mn2-8mn..把下列多項(xiàng)式的括號(hào)去掉，合并