[x+y/2=z+x/3=y+z/4,x+y+z=27]要有过程

问题描述:

[x+y/2=z+x/3=y+z/4,x+y+z=27]要有过程

12x+6y=12z+4x=12y+3z
分成两个等式:
x+y/2 = y+z/4
=>4x+2y= 4y+z
=>4x=2y+z(一)
x+y/2=z+x/3
=>6x+3y = 6z +2x
=>4x = 6z-3y(二)
结合(一)(二)
6z-3y = 2y+z
5z = 5y
z = y
代入(二)
4x = y ×6 - 3y
4x = 3y
x = 3/4y
3/4 y + y + y = 27
3y + 4y + 4y = 108
11y = 108
y = 108/11
z = 108/11
x = 81/11