宸茬煡(x+y)虏=20,(x-y)虏=40.姹

宸茬煡{(x-2)虏-(x+y)虏+y(2x-y)}梅(-2y)=2,姹 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 宸茬煡X虏-Y虏=8,X-Y=2,姹俋虏+Y虏镄勫 宸茬煡(x+y)虏=20,(x-y)虏=40.姹 宸茬煡x虏+y虏+2x-6y+10=0,姹倄^ yx²+y²+2x-6y+10=0,求x^ y 化简 x / y(x+y) - y / x(x+y) = x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x+x+x+y=20 x+x+y=14 x=?y=? 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=? x+y=20,x-y=10,y= y=x(x 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 x+x+x+x+y+y+y=56 x+x+x+y+y=6.4 y+y+y+x+x=7.1 怎么算? 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)