用加减消元法解方程组3y-2x=48,3y+2x=90.再用加减消元法解方程组3s+2t=4,2s-3t=7

{x-y=3 2x+3(x-y)=11 用加减消元法解方程组 ｛x-y=3 2x+3(x-y)=11 用加减消元法解方程组 3x+2y=9 3x-2y=3 用加减消元法解方程组 用加减消元法解方程组3x-2y=1 2x+3y=-7 用加减消元法解方程组{x/3+y/4=2 x/4+y/3=2 用加减消元法解方程组{3x+2y=5 2x-3y=8 ｛x/3+y/4=1 x/3-y/2=1 用加减消元法解方程组 用加减消元法解方程组：x+y=3,x-2y=-3 2x=-3y=4x-2-y+10,用加减消元法解方程组 用加减消元法解方程组｛2X+3Y=8.7｛4X+2Y=12.2 用加减消元法解方程组2x+y=18,3x-2y=13 用加减消元法解方程组 3(x-1)=y+5 2(y+1)=x+1 用加减消元法解方程组{4x-5y=5,2x+3y=-25 用加减消元法解二元一次方程组方程组4x+3y=6和2x-y=4 用加减消元法解二元一次方程组方程组4x+3y=6和2x-y=4 x+y/2+x-y/3=6,4(x+y)-5(x-y)=2用加减消元法解方程组 加减消元法解方程组3x-2y=54x+3y=1 用加减消元法解方程组x-3y=-8 5x-4y=25