先化简再求值{(2x y)(2x-y)-(2x-y)的平方}÷(-二分之一)-搜答案-智慧作业帮

原式=（x-y）（x+2y）除以（x-y）（x-y）-(1-x方y的四次方)-x方y的四次方=(x+2y)除以（x-y）-1当x=根3+根2,y=根3-根2上式=（3倍根3-根2）除以（2倍根2）-1

(x²+xy-2y²/x²-2xy+y²)-(1-xy²)(1+xy²)-x²÷1/y^4=【（x+2y)(x-y)/(x-y)&

3（x-2y）+2（3x+y）=9x-4y（3x²y-2xy²）-（xy²-2x²y)=xy（3x-2y）-xy(y-2x)=xy(5x-3y)=22

xy^3÷(-xy)+(x+2y)(x-2y)=-y^2+x^2-4y^2=x^2-5y^2=2-5=-3再问：不好意思啊！题目......再答：题目怎么了，不影响结果啊。平方还是正的

原式=2xy+x+3x(x−1)÷y(x2+2x−3)(x−1)2=2xy+x+3x(x−1)•(x−1)2y(x−1)(x+3)=3xy，当x=2+3，y=2-3时，原式=1(2+3)(2−3)=1

解3x平方y-[2xy-2(xy-3/2x平方y)+xy]=3x平方y-(2xy-2xy+3x平方y+xy)=3x平方y-(xy+3x平方y)=3x平方y-3x平方y-xy=-xy=-3×(-1/3)

化简为3xy²(xy+2y²)求得24再问：过程呢

原式=2xy^2-4y+xy-xy-3xy^2+4y=-xy^2=-4×（1/2）^2=-1

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

2x²+（-x²+3xy+2y²）-（-x²-xy+2y²）=2x²-x²+3xy+2y²+x²+xy-2y&

原式=-x³y²+2x4次方y²+4x³y²=3x³y²+2x4次方y²把x=2,y=-1代入得原式=3×2³

原式=(x^2-xy)-6x^2+9xy-2x^2+2(2x^2-xy+y^2)=x^2-xy-6x^2+9xy-2x^2+4x^2-2xy+2y^2=x^2-6x^2-2x^2+4x^2+9xy-2

15乘以X的平方加9(4x)^2+3xy-x^2-3xy+9=16(x^2)-(x^2)+9=15(x^2)+9再问：先化简，在求值，同学，我要过程！

[2x（x^2y-xy^2）+xy(xy-x^2)]÷x^2y=(2x^3y-2x^2y^2+x^2y^2-x^3y)÷x^2y=(x^3y-x^2y^2)÷x^2y=x-y=2008-2004=4

[2x（x^2y-xy^2）+xy(xy-x^2)]÷（x^2y）=[2x²y(x-y)+x²y(y-x)]÷(x²y)=2(x-y)+(y-x)=x-y已知x=2008

(2x-3y+5xy)-(x-4y-3xy)=2x-3y+5xy-x+4y+3xy=2x-x-3y+4y+5xy+3xy=x+y+8xy=(x+y)+8(xy)=-3+8*(-4)=-3-32=-35

3x-4xy+3y再问：然后的过程再答：再带入值等于3.5再答：马上再答：给你照片再答：再答：亲采纳哟

原式=1/9x²y²(2x²y-xy²-2x²y+2xy²)=1/9x²y²*xy²=1/9x³y&

[(xy+2)(xy—2)—2(x的平方y的平方—2)]=x²y²-4-2x²y²+4=-x²y²;很高兴为您解答,skyhunter002