﹛x＋y=1,10x＋y=5 1／2

3x(2x＋y)－2x(x-y),其中x＝1,y=1/5 先化简,再求值:[(x＋y)(x-y)-(x-y)²+2y(x+y)]除4y,其中x=2,y=1 ﹛x＋y=1,10x＋y=5 1／2 (x+y)/6+(x-y)/10=1,(x+y)/6-(x-y)/10=5 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? x-y/7 - x+y/10 =1/2 2(x-y)-5(x+y)=3修改、、、、（x-y)/7-(x+y)/10=1/2 2(x-y)-5(x+y)=3 { x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3 { x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3 10/x+y+3/x-y=-5 15/x+y-2/x-y=-1（用换元法解此方程组） 解分式方程：10/(x+y)+3/(x-y)=-5,15/(x+y)-2/(x-y)=-1 3/(X-Y)+10/(X+Y)=-5 2/(X-Y)-15/(X+Y)=1 解分式方程组 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 若5x+y/7x+10y=1/2,则x/y=? 若7x+10y分之5x+y=1/2,则x/y= 若（5x+y）／(7x+10y)=1/2则x/y= 分式的加减:[(x/y-y/x)除以（x+y）+x（1/y-1/x)]除以1+x/y,其中x=5,y=2