x+y+z=59 15x+12y+8z=3*15+2*12+8 怎么算

x+y=8 y+z=12 x+z=10 x+y+z= x+y=8 y+z=12 x+z=10 x+y+z= (x+y-z)(x-y+z)= X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? x+y+z=59,15x:12y=3:2,12y：8z=2:1谢 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 (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 解方程15X=12Y=8Z X+Y+Z=33 x+y+z=15 x+5y+10z=70 x,y,z,各是几? x+y+z=15 x+5y+10z=70 x,y,z,各是几? X+Y-Z=15 X+5Y+10Z=70 求：X、Y、Z (x*x+2)(y*y+4)(z*z+8)=64xyz,求x,y,z 20(x+y)=12(y+z)=15(z+x),且xyz不等于零,求x:y:z= 已知x+y=8,y+z=12,x+z=10,则x+y+z=? 若x+y=8 y+z=12 x+z=10 则x+y+z =多少