x:y=3:5
y:z=2:3
x:y:z=6:10:15
x=6k,y=10k,z=15k
X+Y+Z/2X-Y+Z
=6k+10k+15k/(12k-10k+15k)
=31/17
x:y=3:5,y:z=2:3求X+Y+Z/2X-Y+Z
4个回答
相关问题
-
x+y+z=35 2x-y=5 y/3=z/2 求x,y,z
-
x-5y-3z=0 y+z-3x=3 x+y+3z=14 y+4z=3 z+x-3y=5 2x+y+z=7 2x-z=1
-
x+y+z=2 ① 2x+3y+z=38 ① x+y=3 3x-y-4z=5 ② 3x+4y+2z+56 ② y+z=5
-
证明：（y+z-2x）3+（z+x-2y）3+（x+y-2z）3=3（y+z-2x）（z+x-2y）（x+y-2z）．
-
z/x=3/(y- z)=5/(z+x),求(5x-y)/(y+2z)的值
-
(2X-3Y+Z)-3{X-2[-Z+(X-Y)]-(3Y-5Z)}
-
x-y+z=5 2x+3y+z=-2 x-2y-z=3
-
已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z
-
x,y,z满足x+y+z=3,x^2+y^2+z^2=29,x^3+y^3+z^3=45,求x,y,z,x^4+y^4+
-
x+2z=3 x+y+z=2 2x+y=2 3x-y-4z=5 2y+z=7 2x+3y-2z=0