求Y=X+1/(3X+2) (X>2/3)的最值是求Y=X+1/(3X-2) (X>2/3)的最值

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) y=(2x*x-2x+3)/(x*x-x+1),求值域? 求值域 1,y=(x+2)/(x*x+3x+6) 2,y=3x/(x*x+4) {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? y=(X+1)(X+2)(X+3)求导数 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-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 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|x|=2,|y|=3,|x+y|=-(x+y)求x-y y=3(x-y),x=2(x-y)求x,y的值 x*y=6x-y=1求X Y是多少?X=3 Y=2 求公式! 求导数y=3x-x^2 求y',y'/ x=1 y'/x=0 1奥数题x-2y/x+2y=3,求x-2y/3(x+2y)-3(x-2y)/x-2y的差 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值