x+3y=10 3x+4y=20
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
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
{3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
{4/(x+y)+6/(x-y)=3 {9/(x-y)-1/(x+y)=1
(x+y)(x+2y)(x+3y)(x+4y)=-40
解方程组 10(x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16
解方程组X+Y/2=3X-2Y=10+6X+Y/4