3x+6y=78 3x+4y=72 怎么解

5x+4y=22 4x+y=3y+x 怎么解 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 ｛4/(x+y)+6/(x-y)=3 ｛9/(x-y)-1/(x+y)=1 怎么解二元一次方程组2(x-y)/3-x+y/4=-1和6(x+y)-4(2x-y)=16 解方程组 x-y/3-x+y/4=2 x-y/6-x+y/8=3 解二元一次方程(x+y)/2-(x-y)/3=6 3(x+y)=4(x-y) 解方程组：2(x-y)/3-x+y/4=-1 ,6(x+y)-4(2x-y)=16 3(x+y)—4(x-y)=4,(x+y/2)+(x-y/6)=1.解方程组 解二元一次方程组{3(x+y)-4(x-y)=4,x+y/2+x-y/6=1