3x+y+3z=0,2x+3y-5z=0,求x+y-z的值

问题描述:

3x+y+3z=0,2x+3y-5z=0,求x+y-z的值

z当常数,解得
x=-2z
y=3z
x+y-z=-2z+3z-z=0