4y-y怎么做-搜答案-智慧作业帮

x²y²-4y=1,2xy²+2x²y(dy/dx)-4(dy/dx)=0,dy/dx=(xy²)/(2-x²y)

最后一项是否多了一个y?如果没有那个y,就应当是(xy-1)²+(x+y-2)(x+y-2)=（xy-1+x+y-2）（xy-1-x-y+2）=(xy+x+y-3)(xy-x-y+1)再问：

5（X+2）=2×（5X-1）3（Y-2）+1＝y-(2y-1）4（2X+3)＝8（1-X)-5(X-2)5x+10=10x-23y-6+1=-y+y8x+12=8-8x-5x+10-2x=-123y

=xy(x-y)×[-xy/(x-y)]=-(xy)²=-x²y²

4x的平方-4y的平方+4y-1=4x²-(4y²-4y+1)=4x²-(2y-1)²=(2x+2y-1)(2x-2y+1)

x+y分之x-y除以（y-x）=(x-y)/(x+y)÷(y-x)=(x-y)/(x+y)×(-1)/(x-y).约分=-1/(x+y).负x+y分之1

(2x+3y)(x-4y)=2x²+3xy-8xy-12y²=2x²-5xy-12y²(5x-y)(-x-3y)=-5x²+xy-15xy+3y

我来帮你先

(2x-3y)²-(4y-3x)(3x+4y)=(2x-3y)²+(3x-4y)(3x+4y)=(4x²-12xy+9y²)+(9x²-16y

...把X=4-5y带入到后面的式子,就是3（4-5y)-9y=4然后解出y

(y-4)²=(y-4)(3y-1)(y-4)²-(y-4)(3y-1)=0(y-4)(y-4-3y+1)=0(y-4)(-2y-3)=0y1=4y2=-3/2如果本题有什么不明白

(8x+4y)-(x+4y)=56-218x+4y-x-4y=357x=35x=58*5+4y=564y=56-404y=16y=4

题写错了?再详细些

（x-y)/(2x+2y)=(x-y)/2(x+y)=(x-y)(x+y)/2(x+y)^2xy/(x+y)^2=2xy/2(x+y)^2x-y/2x+2y=(x^2-y+4xy)/2x=(x^2-y

原式=(3x+y+3x-y)(3x+y-3x+y)÷2(2x-y)=12xy÷2(2x-y)=6xy/(2x-y)

（x+y)*(a+2b)怎么做

（x+y)*(a+2b)=a·x+2b·x+y·a+2b·y=ax+2bx+ya+2by

x^4-2x^2y-3y^2+6y-4=(x²-3y)(x²+y)+6y-4如果题目没错就只有到这步了.如果+8y则=(x^2-y）^2-4（y-1）^2(化成平方)=(x^2-y

您好!x^2-y^2-2y-1=x^2-(y^2+2y+1)=x^2-(y+1)^2=(x+y+1)(x-y-1)这里还是考察a^2-b^2=(a+b)(a-b)这个平方差公式,只是这里b是y+1这个

①(a-b)x^2-a+b=(a-b)x^2-（a-b）=（a-b)(x^2-1)=(a-b)(x+1)(x-1)②x^2-4y^2+x-2y=(x+2y)(X-2y)+(x-2y)=(x-2y)(x