求值(2x^2-3XY--5X-1)-搜答案-搜搜考试网

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

[-(xy)/(x-y)^2]^4*[(x^2-xy)/x]^3*x^4/y^10÷[x/(xy-y^2)]^5=(x^4y^4)/(x-y)^8*(x-y)^3*x^4/y^10*[y^5(x-y)

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

有时间打这么多子,没时间把这些简单的知识看看啊再答：再答：再答：再问：第一个先化简再求值的我打错了应该是x的平方y-3x²y-6xy+5xy+2x²y其中x=11y=-6

原式=-3x³y³+6x^4y^4+4x²y³*2x²y=-3x³y³+6x^4y^4+8x^4y^4=-3x³y&su

|x-2|²+(y-3)²=0x-2=0,y-3=0x=2,y=3原式=3xy-[2x-2xy-(3x+xy)-5y]=3xy-(2x-2xy-3x-xy-5y)=3xy-2x+2

x^+(5x^-xy)-2(x^-3xy)=x^+5x^-xy-2x^+6xy=(x^+5x^-2x^)-(xy-6xy)=4x^+5xy=4*(-1/2)^+5*(-1/2)*(-1)=1+5/2=

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

再答：满意请采纳，谢谢了

√x^-2xy+y^2+x^2-6xy+9y^2/x-3y=√(x-y)^2+(x-3y)^2/x-3y由于y>x=y-x+x-3y=-2y=-2√5

3（xˆ2y-2xy+x）-2（2x+5xˆ2y-xyˆ2)=3x²y-6xy+3x-4x-10x²y+2xy²=2xy²-8x&

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！

5xy平方-2x平方y+[3xy平方-(4xy-2x平方y-2x平方y)]＝5xy平方-2x平方y+[3xy平方-4xy＋2x平方y＋2x平方y)]＝5xy平方-2x平方y+3xy平方-4xy＋2x平

若|x+2|+(y-1/2)平方=0,则有：x+2=0且y-1/2=0解得：x=-2,y=1/2所以：3(2x^2y-xy^2)-(5x^2y-4xy^2)这里是不是少打了个y哈!=6x平方y-3xy

x,y都可以解出来了还问

(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

-5(xy-2x^2)+(5xy-x^2)-2(3x^2-5xy)=-5xy+10x^2+5xy-x^2-6x^2+10xy=(10x^2-x^2-6x^2)+(-5xy+5xy+10xy)=3x^2