快,明天要交(2x-y)(x+y)-2(x+y)²+3xy,y=1/6
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知x(x-1)-(x^2-y)=-3求(二分之y-x+2xy)-xy 快,
x+y)(x-y)+(x-y)^2-(6x^2y-2xy^2)/2y,其中x=-2,y=1/3
3x^2+xy-2y,快
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
计算3x[xy-2x(1/y-x/3]+3y(x²-y²)
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
x-y=-1 和 x:2=y:3二元一次方程组求xy 快
已知xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 快救救我~
若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(