x+y=27 50x+45y=1290 求x y

x+y=27 50x+45y=1290 求x y x+y=27 50x+45y=1290 求x和y分别是多少 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/x-x+y/y-(x+y)(x-y)/y² y/x=2 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+y=27 50x+45y=1290 怎么分解 y=x(x 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 y+10x=x+y+9 10y+x=y+10x+27 f(x,y)=x*x*x+y*y*y-9xy+27极值 x+x+x+x+y+y+y=56 x+x+x+y+y=21,x+x+x+x+x+y+y=27,求x=?y=? 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) x-y/x+y=(x-y)²/x²-y²（x≠y) （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y