求y=(1/3)^(x^2-3x+2)的单调性和值域y=1/3的x^2-3x+2的次方

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 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 y=3(x-y),x=2(x-y)求x,y的值 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 1奥数题x-2y/x+2y=3,求x-2y/3(x+2y)-3(x-2y)/x-2y的差 求方程 dy/dx+x(y-x) +x^3(y-x)^2=1的通解~ (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) -2x+3y=3x-2y+1求x.y的大小关系 已知X-Y=3,求X-Y的2次幂减3X+3Y+1 若x-y=3,x^2-y^2=1,求x+y的值 已知|2x-3y|+|3x-y-1|=0,求x,y的值. 已知3x-4y/2x+y=1/2 求x/y的值 已知x-2y/y+3x=1/2,求x/y的值 已知2x-3y/x-y=1/2,求y/x的值. 已知2x-3y/x-y=1/2,求y/x的值. 3x=2y+1;x=9y;求x,y的值? 已知(3x-4y):(x+y)=1:2,求x:y的值