3y(x-1)-x(3y-1)=2,求(x^2+9Y^2)÷6-xy如题

(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=? 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 1奥数题x-2y/x+2y=3,求x-2y/3(x+2y)-3(x-2y)/x-2y的差 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 分式加减的几道题目求速度1 .(x+y)²/（x-z)(y-z) - (y+z)²/（x-z)(y-z) = 2.2x+3y/x-y+2y/y-x-3y/x-y= 若x-y=2(x+y),求代数式x-y/x+y+x+y/x-y求代数式 x+y分之x-y+x-y分之x+y 已知:y=ax的3次方+bx+3,当x=-1/2时,y=-7,试求x=1/2时,y的值 1/x-1/y=3,求2x+3xy-2y/x-y 2x+4y=3 -3x-2y=1 ..求x和y 2x+y=3,3x+2y=1【求X.Y】 已知X-Y=3,求X-Y的2次幂减3X+3Y+1 -2x+3y=3x-2y+1求x.y的大小关系 2^x=4^(y-1) 27^y=3^(x+1)求x-y 2分之x+2y=3分之2x-y=1求x，y