求{3(x-1)+2(y+1)=8 2(x-1)-3y=1解方程要过程 求{0.5x-3y=-1 -2分之1x+5y-3=0

(x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) x+y=8 2x-y=1 求3x+5y 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=? x-2y+3=0 求x^2-(4y+1)x+4y^2+8y 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 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 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 2x+3y-1=y-x-8=x+6求2x-y的值 1 已知x+y/y=7/3 求x+y/x-y等于什么2 若x+4/3=y+3/2=z+8/4 且x+y+z=12 求x、y、z的值 已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x)+4y(-4y-5/2x)的值 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^2-8x+y^2-y+16又1/4=0,求[(x+y)(x-y)-(x+y)^2-2y(x-3y)]÷4y的值 1/x-1/y=3,求2x+3xy-2y/x-y 2分之x+2y=3分之2x-y=1求x，y 2y=x-3 y+2=2x-1 求x y