若0.001^x=1,(-3)^y=-1/27,则x-y=

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 若变量x,y满足约束条件{x>=-1;y>=x;3x+2y 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值? y(x+y)+(x-y)²-（x+y）（x-y）,其中x=-1/3,y=3 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值 若x-y=2(x+y),求代数式x-y/x+y+x+y/x-y求代数式 x+y分之x-y+x-y分之x+y 已知:y=ax的3次方+bx+3,当x=-1/2时,y=-7,试求x=1/2时,y的值 若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y= 若实数x,y满足不等式x-y>=-1,x+y>=1,3x-y 若实数x,y满足不等式x-y>=-1,x+y>=1,3x-y 若x,y满足约束条件,x>=0,y>=0,x-y>=-1,3x+4y 若x,y满足|x-y+1|+(x+y+3)^2=0则x^2-y^2= {3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 y'=(x-y+1)/(x+y-3)通解 若x-y=1,求代数式x(x-y)+y(y-x)+2013的值