x+y=48.2x+4y=100 x是多少,y是多少?如题

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x+y=48.2x+4y=100 x是多少,y是多少?如题 化简 x / y(x+y) - y / x(x+y) = x+x+x+y=60 .x-y=4 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 7x:4y,x:y=( ):( (x-4y)(2x+y)= 5x-4y(y-x)=? y=x(x 程序中,输出x,y,到底是写 x,y 还是 “x,y=”；x,y X+Y/X=2,X/Y=?是（x+y）/x=2哦 y=x+4/x (x y=|-x.x+4x+5| 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? x,y>0,且x+2y=1,u=(x+1/x)(y+1/(4y)最小值是: 已知实数x,y满足（x+y)(x+y+3)-4=0则x+y的值是