x-2y=7 xy=3 则2xy-4y+2x+5=?
已知x-y=4xy,则2x+3xy-2yx-2xy-y
(-3x^y+2xy)-( )=4x^+xy
xy=-2,x+y=3,求代数式(4xy+12y)+[7x-(3xy+4y-x)]
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值
已知xy^2=-2求xy(2x^3y^7+5x^2y
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
已知x+y=5,xy=-3,则x^2y+xy^2,
x*-2xy+3y*=9 4x*-5xy+6y*=30