作业帮5x²-2xy²-[3xy十4y²十(9xy-2y²-2mxy²)十7x²]-1
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/21 04:15:34
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
Solution:x^2-2xy+3y^2=9(1)4x^2-5xy+6y^2=30(2)Eq(1)*5-Eq(2)*2,wehavex^2-y^2=5(3)Eq(2)-Eq(1),wegetx^2+
(-3x^y+2xy)-(4x^+xy)=-3x^y+2xy-4x^-xy=-3x^y+xy-4x^所以填上-3x^y+xy-4x^
5x^2y/-1/2xy*3xy^2=-7.5x²y²
化简1.原式=xy（4x-5y-3x²-4y）=xy（4x-9y-3x²）2.原式=5a-[a³+5a²-2a-2a²+6a)]=5a-(a³
x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2=16x^3y^3-49x^3y^3-45^3y^3=-78x^3y^3如果本题有什么不明白可以追问,
-3(2x²-xy)+4(x²+xy-6)=6x²+3xy+4x²+4xy-24=-2x²+7xy-24
-3(2x^2-xy)+4(x^2+xy-6)=-6x^2+3xy+4x^2+4xy-24=-2x^2+7xy-24再问：thankyou~
x十2y十4/xy,大于等于三次根号下（x*2y*4/xy）,所以最小值应为三次根号8,也就是2
a-2b=(5x²y-3xy²+4xy)-2(7xy²-2xy+x²y)=5x²y-3xy²+4xy-14xy²+4xy-2x&#
∵x-y=4xy，∴2x+3xy-2yx-2xy-y=2(x-y)+3xyx-y-2xy=8xy+3xy4xy-2xy=112．故答案为：112．
(5xy+4x+7y)+(6x-3xy)-(4xy-3y)=5xy+4x+7y+6x-3xy-4xy+3y=(5xy-3xy-4xy)+(4x+6x)+(7y+3y)=-2xy+10x+10y=-2x
已知A=5x^2y-3xy^2+4xy,B=7xy^2-2xy+x^2y.（1）求A-2B的值A-2B=5x^2y-3xy^2+4xy-2*(7xy^2-2xy+x^2y)=5x^2y-3xy^2+4
X=1,Y=2,XY=2;
5xy^2-[3xy^2-(4xy^2-2x^y)]+x^2y-xy^2=5xy^2-3xy^2+(4xy^2-2x^y)+x^2y-xy^2=5xy^2-3xy^2+4xy^2-2x^y+x^2y-
2x平方y-2xy+3xy平方+5+2xy+x平方y-3xy平方-3=2x²y-2xy+3xy²+5+2xy+x²y-3xy²-3=3x²y+2
2xy-{5x-3[xy-1/3x(y+1)]-4xy}=2xy-{5x+x+3xy+xy-4xy}=-6x+3xy-xy