化简5(x-2y)² (-6)(x-2y)³-搜答案-搜搜做题作业网

原式=(9x²+24xy+16y²-4x²+y²-5x²+6xy-y²)÷(-2y)=(30xy+16y²)÷(-2y)=-15x

-6x²y-x+5x²y-2x+x³y+3x=-6x²y+5x²y-x-2x+3x+x³y=-x²y+x³y

设x-y=mx+y=n则6m-2n=143m+n=5解得m=2n=-1即x-y=2x+y=-1解得x=1/2y=-3/2

-（5x+y)-3(2x-3y)＝－5x-y-6x+9y=-11x+8y

2(2x+3y)(3x+2y)-(6x-y)(2x-5y)=12x^2+26xy+12y^2-(12x^2-32xy+5y^2)=12x^2+26xy+12y^2-12x^2+32xy-5y^2=58

方程两边同时进行通分可得[5(x2-16)+96]/(x2-16)=[(2x-1)(x-4)+(3x-1)(x+4)]/(x2-16)再问：不好意思这是两道题再答：这好似第一个原式=(x+y)[(x-

(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)=x-2x-3x-4x-..-10x+y*(1-1/2-1/6-1/12-..1/90

(x-y)^8

(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方=x²-2xy-3y²-x²+4y²-x²+2xy-y²=(x²-

3楼说的好,分类讨论是数学中一种重要的方法,但建议用零点分段法.当6-x=0时其他2个怎么样以此类推例：当6-x≥0时则原式=6-x-2x-1+x+5=10-2x当6-x＜0时则原式=x-6-2x-1

2（2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)=2（4X^2-49Y^2)+X^2-(16X^2-25Y^2)=8X^2-98Y^2+X^2-16X^2+25Y^2=-7X^

1.(-2x^y^)(3x^y^)(-4x^y^)=24x^(1/4-1/2+1/4)y^(-1/3+2/3+2/3)=24x^0y^1=24y2.（6√x)\(3√x√x^5)=18√x^7=18x

[(x-y)/(x+3y)]/[(x^2-y^2)/(x^2+6xy+9y^2)]-xy/(x+y)=(x-y)/(x+3y)*(x+3y)^2/(x-y)(x+y)-xy/(x+y)=(x+3y)/

(x+2y)(x-2y)-(x-4y)(x+4y)+(6y-5x)(6x-5y)=x^2-4y^2-x^2+16y^2+36xy-30y^2-30x^2+25xy=-18y^2+61xy-30x^2

原式=(x-y)/(x+3y)×[(x+3y)^2/(x+y)(x-y)]-2y/(x+y)=(x+3y)/(x+y)-2y/(x+y)=(x+3y-2y)/(x+y)=(x+y)/(x+y)=1

[(x+2y)^2-(x+y)(3x-y)-5y^2]/2x=[x^2+4xy+4y^2-3x^2-2xy+y^2-5y^2]/2x=(-2x^2+2xy)/2x=y-x

（x-2y)²-（2x-y)(-2x-y)+(x-5y)(x+2y)=x²+4y²-4xy-y²+4x²+2xy-5xy-10y²=6x&s

这才是正确答案~

:【(2x-y)(2x+y)+y(y+6x)】÷2x=（4x^2-y^2+y^2+6xy)÷2x=2x+3yx^2代表的是x的平方的意思

x+y=3则y=3-x带入x+2y=9解得x=-3,y=6剩下的都这样解