5x+2y=10 2x+5y=8

(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 3(2X+Y)+(2(2x-Y)=6 (8X+4y)-(10X-5Y)=2 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x X^2-Y^2+6X+10Y-30=0 X^2+Y^2-5X-8Y+21=0 X=?Y=? 2(x-y)=5y,x-y=-5 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 x-y / 5y= (y-x)^2 / ( ) 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x*x+2x+y*y-4y+5=0 x= y= 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5