初中代数练习题.docx

、-15ab2c+8abc-24a3bc2-8abc= .2.(2x2-3xy+4y2)+(x2+2xy-3y2)= .-(3a-2b+2)+(3a-4b-1)= .2x-(x+3y)-(-x-y)-(x-y)= .-(1-x)-1-(x-1)= .6.(?)+(4xy+7x2-y2)=10x2-.(4xy2-2x2y)-( ? )=x3-2x2y+4xy2+=x3-2x2+x-4,B=2x3-5x+3,计算A+B= ;A-B= .-m3-2m+5得-2m4-3m3-2m2-1,则这个多项式等于 .10.-(2x2-y2)-[2y2-(x2+2xy)]= 11.(-y+6+3y4-y3)-(2y2-3y3+y4-7)= .-[7x2-5x-3(1-2x+x2)]= -b2+c-d3=2a+(?)-d3=2a-d3-( ?)=c-( ?).14.[5a2+( ?)a-7]+[( ?)a2-4a+(?)]=a2+2a+,y>0,则|1-x+y|-|x-y|= .已知xv0,yv0,则|x+y|-|5-x-y|= .一个多项式加上-3x2y+2x2-3xy-4得2x2y+3xy2-x2+2xy,这个多项式为 .18.-2(3x+z)-(-6x)+(-5y+3z)= -(2a-4b-6c)+3(-2c+2b)= -x=5时,5(x-2y)2-3(-x+2y)-100= 二、--(x-y)+y2(y-x)---+42x+-30x+-60x+-20x++12x+-66x+-9a2b2c2+-7x--12x+-5x-+9+39x18.-20x2+9x+-24--29x+-35x2--2x3--a-b2--ab2+a--bx2-bx+ax+2b--m2+2mn-5n--4xy-1++m2++4xy+4y2-2x-4y-+y2-x2y2-4xy-1三、分式方程若方程二^十二^-“0有解“2,&「土+眾=°*・€r走的解是"1 6-v ’卡+_KT亍去分母整理得2x4~2〜「「-?+-V=窓+—的解是7•解分式方程:2k-1 k-5(x-l)(x-2)=Cx-2)(z-7)K _ 瓷十72x2-11x-21- +35'x-4 1忑一百 M + .x2+X-2X-1K2-4'1 2x_ 30+1)(盟+2)十仗斗2)(孔-2)—©-2)口十1)1 _ 盘[1 1x+7C2k-DC^十了)2m2-?x+1・x-1,2x 4監 c7亠7-~o =0■X+1矍-1 /・1匹T3^-3x2-12e-3丄十-:.