6x=5y z=2x-5 3y+3x=42 怎么算?
x/2=y/3=z/5 x+3y-z/x-3y+z
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X
已知3X=4X,5Y=6Z求X+Y:Y+Z
{2x+3y-4z=-5 x+y+z=6 x-y+3z=10
解方程组:x+y+z=4,x+y+2z=5,3x+y-z=6
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值
已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值.
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
x=3,y=4,z=5,求以下表达式的值,怎么算 (x && y)==(x || z) (x>y)+(y!=z) ||