怎么样解6/7y=x 10/9x=y-120这个方程

怎么样解6/7y=x 10/9x=y-120这个方程 2/5x+2/3y=-10 ① x/3-y/9=1 ② 解方程组 x-y/5-x+y/2=-1/10① x-y/7-x+y/6=1/2② (x+y)/6+(x-y)/10=1,(x+y)/6-(x-y)/10=5 {6/x+y+10/x-y=30 6/x+y-10/x-y=-1 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 帮忙解一些方程组(1)3x-2y=6 2x+3y=17 (2)5x+6y=15.2 3x-2y=-0.4(3)2(x+y)-3y=7 4(x-9)=3(y-2)(4)3(x+y)-4(x-y)=4 x+y/2+x-y/6=1 解方程组x+y/6+x-y/10=3,x+y/6+y-x/10=-1x+y/6+x-y/10=3 ①x+y/6+y-x/10=-1 ② 谁会解10x+y=6(x+y)+3 10y+x=4(x+y)+9 解方程组：{x(x+y+z)=6 {y(x+y+z)=9 {z(x+y+z)=10 用加减法解方程组:{(x+y)/6+(x-y)/10=3 (x+y)/6+(y-x)/10=-1 x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9用代入法解 x+y=3 x+2y=9 3/x+1=y y-x=3 y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9 y-x=3 解方程组：{4/x+y+6/x-y=3 9/x-y-1/x+y=1} 解方程组{4/x+y+6/x-y=3, 9/x-y-1/x+y=1 解二元一次方程 {3(x+y)-4(x-y)=-9 x+y/2+x-y/6=1 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6(x-y)-7(x+y)=21 2(x-y)-5(x+y)=-1 x+y=5① x=3y+2① 9x-5y=1① 3x-2y=11① x-2y=y+1① 2x-y=7② x+3y=8② 6x-7y=2② 2x+3y=16② 2x-3y=10②3x+2y=y+1①2x-3y=10②D