2x+3y=10 3x+7y=34

3x+x+4y+(90+10)x=3y-(2x+y)+510y=34x 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 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 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) x+y=2,3x+7y=10 求x和y 求几个方程组的答案 ｛2x+y=2 {3x-y=7 x=?y=?{x+2y=50 {3x=2y+6 x=?y=?{x+y=40 {10x+8y=370 x、y=?{x+y=5.8 {y=3x+0.6 x=?y=? (x+y)(2x-3y)=? 7y(x-3y)-2(3y-x)=0 .x=?,y=? (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 3x+5y-(x+y)=6 2(x+y)-3x=-7