x/18=y-12/60 x/15=y+12/60

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*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少 (12-x)*y+x*2=26 (15-x)*y+y*2=35(12-x)*y+x*2=26 (15-x)*y+y*2=35 x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x+x+x+y=60 .x-y=4 x/18=y-12/60 x/15=y+12/60 x.y都是自然数,且x(x-u)-y(y-x)+12,求x.y得值快1且x(x-y)-y(y-x)=12 {2x+y=15 x+2y=18 x+y=18 x/12 +y/8 =20 计算18x+9y=14x+15y 12x+20y=20x+15y [(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11,y=1/12,化简再求值. 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=15y 解方程 x(x+y+z)=6 y(x+y+z)=12 z(x+y+z)=18 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18