求y=(1/3)∧(1-2x)/(x+1)的定义域和值域我们才刚接触这类题,劳驾说清楚一点哦,

(x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 {(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 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) 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 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 y=2x∧2+2x+3/x∧2+x+1求值域, 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 1奥数题x-2y/x+2y=3,求x-2y/3(x+2y)-3(x-2y)/x-2y的差 x+2y=2x+y+1=7x-y 求：2x-y? 若x*x+y*y=x+y-1/2,求x,y的值如题 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~