解方程组4x+5y=51 6x-7y=-25

解方程组4x+5y=51 6x-7y=-25 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 解方程组：｛4x+5(x-y)=30,4y-3(x-y)=6 2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 解方程组 解方程组﹛2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 解方程组 x+y/5+x-y/2=7 4(x+y)-5(x-y)=2 解方程组6(x-y)-7(x+y)=21 2(x-y)-5(x+y)=-1 解方程组x+y/2+x-y/2=7,4(x+y)-5(x-y)=2... 解方程组 X+Y/2+X-Y/3=6 4[X+Y]-5[X-Y]=2 解二元一次方程组{x+y/2+x-y/3=6,4(x+y)-2=5(x-y) 解方程组:{二分之x+y+二分之x-y=6,4(x+y)-5(x-y)=2() 解方程组2分之x+y+3分之x-y=6 4(x+y)-5(x-y)=2 解方程组 {(x+y)/2+(x-y)/3=6 5(x+y)-2(x-y)=4 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12 用代入法解此方程组：（x+y)/2+(x-y)/3=6 4(x+y)-5(x-y)=2求方程组的正整数解：x+y+z=7 2x+3y+4z=20 六年级三道关于方程的数学题. 解方程组{-x+2y+3z=12 {2x-2y+5z=13 {3x+2y+z=10 解方程组{2(x+y)-3(x-y)=1 {6(x+y)+7(x-y)=51 此题去括号,变简易方程组再做.已知方程组{2x-y=0 {2x+y=m 和方程组{x-y=5 {2x-y=n-1 解方程组{4X+3Y=5 6x-5Y=7的解 解方程组{5x-6y=9 7x-4y=-5