x 2y/2x y怎么化简

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/03 21:24:44
若x+y=2,xy=-4,求x2y+xy2+1的值

(x+y)(xy)=x^2y+xy^2=-8原式=-7

化简求值①化简:4ab+8-2b2-9ab-6②先化简,再求值:已知3x2y-[2x2y-3(2xy-x2y)-xy],

(1)4ab+8-2b2-9ab-6=-2b2-5ab+2(2)原式=3x2y-2x2y+6xy-3x2y+xy=-2x2y+7xy,当x=-1,y=-2时,原式=-2×(-1)2(-2)+7×(-1

已知A=x3-2y3+3x2y+xy2-3xy+4,B=y3-x3-4x2y-3xy-3xy2+3,C=y3+x2y+2

因为A+B+C=x3-2y3+3x2y+xy2-3xy+4+y3-x3-4x2y-3xy-3xy2+3+y3+x2y+2xy2+6xy-6=1,所以,对于x、y、z的任何值A+B+C是常数.

先化简,后求值.[2x(x2y-xy2)+xy(xy-x2)]÷x2y,其中x=2013,y=2012.

[2x(x2y-xy2)+xy(xy-x2)]÷x2y=[2x3y-2x2y2+x2y2-x3y]÷x2y=x-y,把x=2013,y=2012代入上式得:原式=x-y=2013-2012=1.

2(x2y+xy)-3(x2y+xy)-4x2y其中x=-2,y=12

原式=2x2y+2xy-3x2y-3xy-4x2y=-5x2y-xy当x=-2,y=12时,原式=-9.

先化简后求值:4x2y-[6xy-3(4xy-2)-x2y]+1,其中x=2,y=-12

原式=4x2y-6xy+3(4xy-2)+x2y+1=5x2y+6xy-5当x=2,y=-12时,原式=5×4×(-12)+6×2×(-12)-5=-21.

x+y=5,xy=2,求代数式-x2y-xy2的值

解-x²y-xy²=-xy(x+y)=-2×5=-10

计算:3xy(x2y-xy2+xy)-xy2(2x2-3xy+2x)因式分解

3xy(x²y-xy²+xy)-xy²(2x²-3xy+2x)=3x³y²-3x²y³+3x²y²-

当x等于2012,y等于2013时,求[3x(x2y-xy2)+xy×(3xy-2x2)]除以x2y的值.题目出完后,小

x=2013,y=2013[3x(x²y-xy²)+xy×(3xy-2x²)]/(x²y)=[3x²y(x-y)+x²y×(3y-2x)]/

分解因式:x2y+2xy+y=______.

原式=y(x2+2x+1)=y(x+1)2,故答案为:y(x+1)2.

分解因式:8x2y-8xy+2y=______.

8x2y-8xy+2y,=2y(4x2-4x+1),=2y(2x-1)2.

先化简,再求值 3x2y-[2xy-2(xy-32

原式=3x2y-[2xy-2xy+3x2y+xy],=3x2y-3x2y-xy,=-xy,当x=3,y=-13时,原式=-3×(-13)=1.

已知X2+Y2+4=2X+XY+2Y,则X2Y的值是多少?

由题意得(x-2)平方+(y-2)平方+(x-y)平方=0,故x=y=2,故x平方y=8

化简求值:2(x2y+xy)-3(x2y-xy)-4x2y,其中x=-1,y=1.

原式=2x2y+2xy-3x2y+3xy-4x2y=-5x2y+5xy,当x=-1,y=1时,原式=-5×(-1)2×1+5×(-1)×1=-5-5=-10.

化简求值:[x(x2y2-xy)-y(x2-x3y)]÷3x2y,其中x=3,y=-1.

原式=[x3y2-x2y-x2y+x3y2]÷3x2y=(2x3y2-2x2y)÷3x2y=23xy-23;当x=3,y=-1时,原式=23×3×(-1)-23=-83.

化简并求值:(2x2y-2xy2)-[(-3x2y2+3x2y)+(3x2y2-3xy2)],其中x=−12,y=2

原式=2x2y-2xy2+3x2y2-3x2y-3x2y2+3xy2=-x2y+xy2,当x=-12,y=2时,原式=-(−12)2×2+(-12)×22=-52.

若x-y=3,xy=-2,则xy2-x2y的值是______.

原式=-xy(x-y),当x-y=3,xy=-2时,则原式=-3×(-2)=6.故答案为:6.

已知A=8x2y-6xy2-3xy,B=7xy2-2xy+5x2y,若A+B-3C=0,求C-A.

由题意得:3C=A+B=8x2y-6xy2-3xy+7xy2-2xy+5x2y=13x2y+xy2-5xy,∴C=13x2y+xy2−5xy3,故:C-A=13x2y+xy2−5xy3-(8x2y-6

当x等于1,y等于2时,求代数式3xy2-【2xy2-2(xy-1.5x2y)】+xy-3x2y的值

解3xy²-[2xy²-2(xy-1.5x²y)]+xy-3x²y=3xy²-(2xy²-2xy+3x²y)+xy-3x²