{2100x+700y=（2100+700）*3% {900x+2700y=（900+2700）*5%求出这个方程组的解【只写x= y= 】

2100x+700y=84;900x+2700y=180的解韪步骤 {2100x+700y=（2100+700）*3% {900x+2700y=（900+2700）*5%求出这个方程组的解【只写x= y= 】 解方程 Y=X+Z Y-Z=2 100Z+10Y+X-(100X+10Y+Z)=99 Y=X+ZY-Z=2100Z+10Y+X-(100X+10Y+Z)=99 方程组{x+y+z=50,1500x+2100y+2500z方程组是{x+y+z=50,1500x+2100y+2500z=90000 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简 x / y(x+y) - y / x(x+y) = x+y=50 2100x+2500y=90000 求方程的解 x+y+z=501500x+2100y+2500z=90000 三元一次方程组 1500x+2100y+2500z=90000 x+y+z=50 x+y+Z=50 1500x+2100y+2500z=90000 x+y=50,1500x+2100y=90000怎么解 求过程 要详细 x+y=50和1500x+2100y=900000的解是多少 x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 怎么解( ⊙ o ⊙ {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 快 急 x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? y=x(x x+y=700,400-y=2x,求x和y.