m为何正整数时,方程组mx+y+z=0 3mx+（m-1）y+（2m-1）z=0 2mx+3y+（m+3）z=0

m = 5,x = -1, y = -6, z = -1----------------令x=-1,则有y + z = m（一式）(m-1)y + (2m-1)z = 3m（二式）3y +(m+3)z = 2m（三式）将一式变形,有z = m-y,带入二式（m-1）y + (2m-1)(m-y) = 3m,整理得y = 2m-4.将z ...