(3x y) 4=(6x 5y)=1
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/21 22:50:18
根据题意得,x+1=0,2x-y+4=0,解得x=-1,y=2,∴x5y+xy5=(-1)5×2+(-1)×25=-2-32=-34.故答案为:-34.
1.2(Xy+Xy)-3(Xy-xy)-4Xy=2*2xy-0-4xy=4xy-4xy=02.1/2ab-5aC-(3acb)+(3aC-4aC)=1/2ab-5ac-3acb-ac=1/2ab-6a
(1)4x2m+1y的系数是4,次数是2m+2;-5x2y2的系数是-5,次数是4;-31x5y的系数是-31,次数是6;(2)由(1)可得2m+2=8,解得m=3.
(1)已知2x+xy=10,3y+2xy=6,求4x+8xy+9y的值.式子1乘以2加式子2乘以3就得到4x+8xy+9y=38;(2)如果关于字母x的代数式-3x+mx+nx-x+10的值与x的取值
原式=3xy+6y-xy+6x=2xy+6(x+y)=2*(-2)+6*4=24-4=20
5xy+4x+7y+6x-3xy-4xy+3y=5xy-3xy-4xy+4x+6x+7y+3y=(5-3-4)xy+(4+6)x+(7+3)y=-2xy+10x+10y=-2xy+10(x+y)因为x
3xy-[2xy-2(xy-2分之3xy)+xy]+3xy=6xy-[2xy-2xy+3xy+xy)=6xy-4xy=2xy=2×3×3分之1=2
1.已知x+y=-4,xy=3,求5(xy/2+2y)+[6x-(2xy+y-3x)]的值5(xy/2+2y)+[6x-(2xy+y-3x)]=5xy/2+10y+6x-2xy-y+3x=xy/2+9
三分之二x(3m+1)y3=2/3x^(3m+1)y^3-四分之一x5y(2n+1)=-1/4x^5y^(2n+1)由于二者是同类项,则有3m+1=5,m=4/32n+1=3,n=1,5m+3n=5*
3(xy+2y)-(xy-6x)=3xy+6y-xy+6x=2xy+6(x+y)=2×(-2)+6×4=-4+24=20
3x-5y=k(1)2x+y=-5(2)(2)*510x+5y=-25(3)(1)+(3)13x=k-25x=(k-25)/13y=-5-2x=(-15-2k)/13x
先把代数式(5XY+4X+7Y)+(6X-3XY)-(4XY-3Y)化简(5XY+4X+7Y)+(6X-3XY)-(4XY-3Y)=5XY+4X+7Y+6X-3XY-4XY+3Y=-2XY+10X+1
唉,肯定是老师布置的作业了,还拿来问百度啊?!自己想.
(7xy+4x-7y)+(6x-3xy)-(3y+4xy)=7xy+4x-7y+6x-3xy-3y-4xy=10x-10y=10(x-y)=10*3=30
[3xy(1-x)-6xy(x-1/2)]*2x*(-xy)平方=(3xy-3x²y-6x²y+3xy)(2x³y²)=12x^4y³-18x^5y&
3x^2y-[2xy^2-4(1/2xy-3/4x^2y)+xy]+3xy^2=3x^2y-2xy^2+2xy-3x^2y-xy+3xy^2=xy^2+xy由x=3,y=-1/3得:原式=3*1/9-
-3(2x-xy)-4(-6+xy+x)=-6x+3xy+24-4xy-4x=-10x-xy+24=-10+1+24=15先化简.后代入求值
1、2X^2+XY=10,得4x^2+2xy=203Y^2+2XY=6,得9y^2+6xy=18两式相加即可4X^2+8XY+9Y^2=20+18=38第2题-3X^2+MX+NX^2-X+10=(N
[2xy^2-2(xy-1/2x^2y)]+3xy^2=xy[2y-2+x]+3xy^2=xy(2y-2+x+3y)=xy(5y-x+2)代入x=3/4,y=-1=-3/4(-5-3/4+2)=45
再问:能把第三题重新发一遍吗?再答:这三个题本质上式连在一起的再答:这道题应该是希望杯的试题