2Y-X-1=18与12x-6y=18x+y 的方程组

2Y-X-1=18与12x-6y=18x+y 的方程组 一道二元二次方程组 x(x+y)=12 与 y(x-2y)=1 3/X+2/Y=6/1等介于?（X不等于18）A.x/3+y/2=1/6 B .3Y+2X C.X=18Y/Y-12 D .Y=12X/X-18 3x-y+x=3 4【X-y-1】=3【1-y】-1 5x-4y+4x=3 2x+y-3x=11 【 x除以2 】-【y 除以3】 =2 2x+7y-3x=19 x+y+x=12 3x+2y-x=18 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 方程题4道1.4(x-y-1)=3(1-y)+3.5 (x/2)+(y/3)=2 2.2(x-y)/3-(x+y)/4=13/6 6(x+y)-4(2x-y)=16 3.3x-y+z=3 2x+y-3z=9 x+y+z=12 4.5x-4y+4z=13 2x+7y-3z=19 3x+2y-z=18 x,y满足3x+y=18 x≥1,y≥6 求xy的最大值与最小值 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 y=（x×x+1）^(1/2)+（x×x-6x+18）^(1/2)求y最小值 解方程 x(x+y+z)=6 y(x+y+z)=12 z(x+y+z)=18 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18 (计算方程组x+y)/2=6-(x-y)/3,6(x+y)-5(x-y)=18 解方程组{2(x-y)/3 - x+y/4=-1 6(x+y)-41(x-y)=12 解二元一次方程{5X-2y=3 X+6y=7 {5x+4y=-3 2x-3y=8 {x+Y+Z=26 x-Y=1 2x-Y+z =18{x/3+Y/5=3 X/2- 2Y/5=1 快 1 .{5X-2y=3 X+6y=7 2.{5x+4y=-3 2x-3y=8 3.{x+Y+Z=26 x-Y=1 2x-Y+z =18 4.{x/3+Y/5=3 X/2- 2Y/5=1 已知:x^2-y^2=18,x+y=6,求x,y的值 2x-1-3(y-2)=x 2(x-1)-y=4y-18,