x-9=y+6 xy=(x-9)(y+6)
已知x-y=3xy,且xy不等于0,则-3x+6xy+3y/(7x-5y)-9xy-(3x-y)
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
x*-2xy+3y*=9 4x*-5xy+6y*=30
{xy\x+y=6 xy\9x+4y=1
2 21.(2x+3y) -(x+2y) 2 2 2 22.3|x-3|+x -6xy+9y =0 则x y+2xy=?
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
化简求值:根号x^-2xy+y^2 + x^2 -6xy+9y^2/x-3y,其中x=根号3,y=根号5
若xy/(x+y)=3,则(6x+4xy+6y)/(9x+4xy+9y)=______
已知|3-y|+|x+y|=0,求x-y/xy的值.x-y/xy =(-3-3)/【(-3)×3】 = -6/(-9)
已知实数x,y,z满足x=6-y,z2=xy-9,求证:x=y.
已知:有理数x,y,z满足x=6-y,z的方=xy-9,求证x=y
已知有理数x,y,z满足x=6 - y,z2=xy -9,试说明x=y