求y=x^2-3x-2-3/x+1/（x^2）,(x>0)最小值,谢谢

y=(2x*x-2x+3)/(x*x-x+1),求值域? 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 求值域 1,y=(x+2)/(x*x+3x+6) 2,y=3x/(x*x+4) (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) y=(X+1)(X+2)(X+3)求导数 {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x(x+1)-(x²+y)=3求2/x²+y²-xy 求方程 dy/dx+x(y-x) +x^3(y-x)^2=1的通解~ 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 函数,y=3x/(x^2+x+1) ,x 函数y=3x/(x^2+x+1) （x 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 x²-4x-1=0,求(2x-3)²-(x+y)(x-y)-y² 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y y=3(x-y),x=2(x-y)求x,y的值 求y=x(x*x+1/x+1/x*x*x)的导数 答案是3x^2-2/x^3