370x+393y=155000,90

370x+393y=155000,90 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简 x / y(x+y) - y / x(x+y) = 3x+x+4y+(90+10)x=3y-(2x+y)+510y=34x x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 3x+y=90 3y+x=58 2x+y=90 y：x=4:7 5（x+y)+3(x-y)=90 5(x+y)-3(x-y)=30,解二元一次方程组 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 求几个方程组的答案 ｛2x+y=2 {3x-y=7 x=?y=?{x+2y=50 {3x=2y+6 x=?y=?{x+y=40 {10x+8y=370 x、y=?{x+y=5.8 {y=3x+0.6 x=?y=? X+Y=90,X/Y=5,请问X等于几?Y等于几? 解方程组 x+y=110 95%x+84%y=(x+y)90% X+y=20 90x- 80x+60y-50y=260 怎么解 x+x+x+x+y+y+y=56 根据x=3y填表 x=3 x=?x=18 x=?x=90 x=?x=?y=?y=2 y=?y=4 y=?y=12 y=2.5不对！是x=3 y=？x=？y=2 x=18 y=4，x=？y=4，x=90 y=？x=？y= 12，x=？y=2. x+y+z=12 x-y+z=2 x-z+y+a=90 x+y+a+z=100,求x y z a