作业帮5x+4y＝50*(5+4)
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/18 09:04:06
|2-x|+|x-y+4|=02-x=0,x-y+4=0x=2,2-y+4=0,y=63（x-y）-5（x-y）^2-3（x-y）+（y-x）^2+4（x+y）^2+3（y-x）=-4（x-y）^2+
原式=(9x²+24xy+16y²-4x²+y²-5x²+6xy-y²)÷(-2y)=(30xy+16y²)÷(-2y)=-15x
x-y+5x-4x=2x-y
-x^y^7+y^8)(这里有问题,x的几次方?再问：就是一次方再答：(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-xy^7+y^8)(x^2+xy+y^2)=（x^8-x^7y+x^
2（x+2y）＝x²+y²+5整理得(x-1)^2+(y-2)^2=0x=1,y=2(x²+y²)/(3x-4y)=-1
化简得：-x+7y=11①7x+3y=27②①式×7得：-7x+49y=77③②+③得：52y=104∴y=2代入①得：x=3∴x=3,y=2再问：亲，是代入法哦！再答：代入法①式得3x+3y-4x+
（x+2)(x+3)=x²+5x+6(x-4)(x+1)=x²-3x-4(y+4)(y-2)=y²+2y-8(y-5)(y-3)=y²-8y+15x²
楼上的全错,{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²}÷(-4x)={9X²-(5x²-xy-25x²+5y²)-(x&s
(x*x+y*y)(x*x+y*y)-4x*x*y*y=(x^4-2x^2y^2+y^4)=(x^2-y^2)^2=0x^2=y^2x/y=±1(x*x+5xy+y*y)/(x*x+2xy+y*y)=
=25x²-9y²+9x²-24xy+16y²=34x²-24xy+7y²
X^2表示平方X^2+4X+4+Y^2-2Y+1=0(X+2)^2+(Y-1)^2=0因为平方大于=0所以X+2=0Y-1=0X=-2Y=1X^2+Y^2=5
4x=5y,x/y=5/4(x+y)/y=x/y+1=5/4+1=9/4
1)(2x+5y)(2x-5y)(-4x^2-25y^2)=-(4x^2-25y^2)(4x^2+25y^2)=-(16x^4-625y^4)=625y^4-16x^42)[（x+y)(x-y)-(x
（5x+3y)(3y-5x)-(4x-y)(4y+x)=(3y)^2-(5x)^2-(4x^2+15xy-4y^2)=9y^2-25x^2-4x^2-15xy+4y^2=13y^2-15xy-29x^
(3x-4y)(5x-4y)-(7x-8y)(6y-5x)=15x²-12xy-20xy+16y²-（42xy-35x²-48y²+40xy）=15x²
1,-3再问：过程。。。再答：★（x²－2x)+（y²－4y）=5★（x－1）²+（y－2）²=1+4－5★（x－l）²=0,（y－2）²=
[(x+2y)²-（x+y)(3x-y)-5y²]÷(2x),其中x,y满足x²+4x+y²-y+17/4=0将x²+4x+y²-y+17/
(x+y)²+4(x+y)-5=（x+y+5)(x+y-1)(2a+b)²-4(2a+b)+3=(2a+b-3)(2a+b-1)6y²-11xy-10x²=(2