13x+11y=129 11x+13y=135 解方程组

{x=y-3 {x+y=11 {2x+y=13 {3x-2y=81.{x=y-3 {x+y=112.{2x+y=13 {3x-2y=8 x+x+x+x+y=40 x+y= 13x=y= {x-y=2,4(x-y)-y=5 {4x-3y=11,2x+y=13 13x+11y=129 11x+13y=135 解方程组 [(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11,y=1/12,化简再求值. 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 6(x+y)的平方-11(x+y)(x-y)+3(x-y)的平方=? 若x,y是正整数,且满足x(x+y)-y(x+y)=11求x+y的值 若x、y为正整数,且满足x(x+y)-y(x+y)=11,求x,y的值 求解二元一次方程组（要详细的步骤）2x+y=13 3x+2y=247x+3y=69 2x-y=162x-y=7 x+2y=11 50=11+x+y=7+x+z=y+13+z x=?y=?z=? 4x+9y=12 3y-2y+5z=11 5x-6y+7z=13 求：x y z等于多少 13X+11Y=1240, 解下列方程组{x+y-z=9;y+z-x=13;z+x-y=11}要过程 x+y=11,x+z=8,y+z=13求x ,y,z各是多少? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2