3分之x y-4分之x-y=5-搜答案-智慧作业帮

原式=（2x+y）/（5xy-6xy）×（1/2）（x+2y）=（x+y）/（-xy）×（1/2）（x+y）=（-xy）/（2x+2y）=（-xy）/2(x+y)=（1/2）×（-xy）/(x+y)当

y分之x等于3分之4--------------------------这题分母是y,分子是x2x²+3xy-5y²分之3x²-5xy+2y²---------

原方程=（2X+5y）*（x-y）分之（3X-2y）*（x-y）=2X+5y分之3x-2y②并且X/Y=4/3所以3X=4yX=4/3*y①把①带入②可得=6\23这个解法是原方程先化简的...比较简

=(2X/3Y)*(3X/4Y)*(4/xy)=(2x*3x*4)/(3y*4y*xy)=2x/(y^3)

因为x-y=4xy所以x-2xy-y=2xy2x+3xy-2y=11xyx-2xy-y分之2x+3xy-2y=5.5

xy/(x+y)=51/x+1/y=1/5yz/(y+z)=7/21/y+1/z=2/7zx/(z+x)=41/x+1/z=1/4(xy+yz+zx)分之xyz=1/(1/x+1/y+1/z)=280

xy/(x+y)=2∴xy=2(x+y)(3xy-x-y)/(3x-5xy+3y)=[6(x+y)-x-y]/[3x+3y-10(x+y)]=5(x+y)/[-7(x+y)]=-5/7

令x/3=y/4=z/5=kx=3ky=4kz=5k原式=(3k)^2+(4k)^2+(5k)^2/3k*4k+4k*5k+3k*5k=50k^2/47k^2=50/47

因为X+Y分之XY=2,所以XY=2(X+Y)代入后面的分子式得：13（X+Y)/5(X+Y)=13/5

1.已知x+y=-4,xy=3,求5(xy/2+2y)+[6x-(2xy+y-3x)]的值5(xy/2+2y)+[6x-(2xy+y-3x)]=5xy/2+10y+6x-2xy-y+3x=xy/2+9

∵y分之x=5∴x=5y(4x²-5xy-6y²)分之(x²-2xy+3y²)=(100y²-25y²-6y²)分之(25y

(3x+2y)(4x-5y)-11(x+y)(x-y)+5xy=12x²-7xy-10y²-11x²＋11y²＋5xy=x²-2xy＋y²=

答案11分之14看图

答案是11分之14. 求采纳

解(-3/4x²y-3/5xy²)(-2/3xy)²=(-3/4x²y-3/5xy²)(4/9x²y²)=-1/3x^4y

xy/(x+y)=2(x+y)/xy=1/21/x+1/y=1/2(3x-xy+3y)/(-x+3xy-y)=(3/y-1+3/x)/(-1/y+3-1/x)=[3(1/x+1/y)-1]/[(3-(

把括号打开7X+4Y+XY-5Y-6X+6XY=X-Y+7XY=5+7*(-3)=-16

(7x+4y+xy)-6(六分之五y+x-xy)=7x+4y+xy-5y-6x+6xy=x-y+10xy把x-y=5和-xy=3代入x-y+10xy=5+10*(-3)=5-30=-25所以原式的值是

x/3-y/4=3x+2y==>4x-3y=36x+24y==>①32x=-27y==>x=-27y/32②(4x-3y)^2=(36x+24y)^2②==>16x^2+9y^2-24xy=1296x

x=4,y=2