若X:4=5:Y,则XY= ( );若5X=7Y,则X:Y= ( ):( ).
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
若1/x+1/y=2,则(2x-xy+2y)÷(3x+5xy+3y)
若m=x^3-3x^2y+2xy^2+3y^3,n=x^3-2x^2y+xy^2-5y^3,则2x^3-7x^y+5xy
若x-y=1,xy=5,则x²y-xy²=?
若正数x,y满足x+3y=5xy,则3x+4y的最小值
若正数x、y满足x+3y=5xy,则3x+4y的最小值是多少
已知x-y=3xy,且xy不等于0,则-3x+6xy+3y/(7x-5y)-9xy-(3x-y)
若x,y满足等式|x+2|+(y-3)^2=0,则(5x^2 y+5xy-7x)-(4x^2y+5xy-7x)的值为?
若实数x,y满足1/x-1/y=5,则分式3x-2xy-3y/x+xy-y的值等于?
若x/3y=y/(2x-5)=(6x-15y)/x,则(4x^2-5xy+6y^2)/(x^2-2xy+3y^2)的值为
若(2x-14xy-2y)除以(x-2xy-y)=4,则1/x-1/y=