化简(x-y分之一)除以(y-x分之一)-搜答案-搜狗做题网

解题思路：本题目关键1/x+1/y=1/3变型，得到x-y和xy的关系式。解题过程：

x的平方+y的平方+2x+4y+5=0x平方+2x+1-1+y平方+4y+2平方-4+5（x+1）平方+（y+2）平方=0x=-1y=-2代入-2+（-1）=-3

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

1/x-1/y=10(y-x)/xy=10y-x=10xy所以原式=[3(y-x)-6xy]/[(y-x)-2xy]=(30xy-6xy)/(10xy-2xy)=24xy/8xy=3

X分之一减y分之一=(y-x)/xy=3y-x=3xy2X一14Xy一2y除以x一2xy一y=[2(x-y)-14xy]/[(x-y)-2xy]=[-6xy-14xy]/[-3xy-2xy]=4

是,但不是分式方程分式是指分母中有未知数的式子

zy分之1+z

1/x-1/y=(y-x)/xy=3y-x=3xyx-y=-3xy原式=[2(x-y)-3xy]/[(y-x)+xy]=[2×(-3xy)-3xy]/(3xy+xy)=-9xy/4xy=-9/4

x的二分之一次方减y的二分之一次方的差除以x的四分之一次方减y的四分之一次方的差=[(x^(1/4))^2-(y^(1/4))^2]/[x^(1/4)-y^(1/4)]=x^(1/4)+y^(1/4)

【(x-y)^2+(x+y)(x-y)】除以2x=(x-y)*(x-y+x+y)/2x=(x-y)*2x/2x=x-y

1/x-1/y=3通分(y-x)/xy=3y-x=3xyx-y=-3xy原式=[(x-y)-xy]÷[5(x-t)+xy]=(-3xy-xy)/(-15xy+xy)=-4xy/(-14xy)=2/7

1/(x+y)=(x-y)/(x²-y²1/(x-y)=(x+y)/(x²-y²

xy(1/x-1/y)=5xyy-x=5xyx-y=-5xy原分式=3(x-y)+5xy/(x-y)-3xy=-10xy/-8xy=5/4

1/x+1/y=(x+y)/xy=2x+y=2xy(3x+7xy+3y)/(2x-5xy+2y)=[3(x+y)+7xy]/[2(x+y)-5xy]=(6xy+7xy)/(4xy-5xy)=13xy/

[(2x+y)(2x-y)-(2x-3y)^2]÷2y=[4x^2-y^2-(4x^2-12xy+9y^2)]÷2y=[4x^2-y^2-4x^2+12xy-9y^2]÷2y=[-10y^2+12xy

x(1/y+1/z)+y(1/z+1/x)+z(1/y+1/x)=(x+y)/z+(x+z)/y+(y+z)/x=-1-1-1=-3

分母有未知数所以是分式再问：两个分式相加还是分式？再答：是的只要分母有未知数就是分数，不管有没有加减乘除的符号

可知x≥0,y≥0(x-y)/(√x+√y)-(x-2√xy+y)/(√x-√y)=(√x+√y)(√x-√y)/(√x+√y)-(√x-√y)²/(√x-√y)=(√x-√y)-(√x-√

根号2x乘以根号y分之x乘以（根号x分之y除以根号y分之一）=根号2x^2/y*（根号y/x*根号y）=根号2x^2/y*根号y^2/x=根号2x/y再代入x、y的值就可以了.

B