求y=(1／2)∧(x∧2-2x-3)的单调区间.及y=In(x∧2+4x)的单调区间

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 若x*x+y*y=x+y-1/2,求x,y的值如题 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 设y=(2x+1)∧3x,求y的二次导数 1奥数题x-2y/x+2y=3,求x-2y/3(x+2y)-3(x-2y)/x-2y的差 y=2x∧2+2x+3/x∧2+x+1求值域, 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) 设随机变量(X,Y)的概率密度为f(x,y)=1/2(x+y)e∧-(x+y),x>0,y>0.0其他.问X和Y是否相互独立,求Z=X+Y的概 已知有理数x,y满足关系式y=[√(x^2-1)+√(1-x^2)/(x-1)]-x+2,求x∧y的值. -2x+3y=3x-2y+1求x.y的大小关系 若x-y=3,x^2-y^2=1,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