x+2y-z=3.①
2x+y+z=5.②
3x+4y+z=10...③
①+②得3x+3y=8④
③-②得x+3y=5⑤
④-⑤得2x=3得x=3/2
带入⑤求得y=7/6
再把x=3/2,y=7/6带入②求得z=5/6
即得方程组的解为
x=3/2
y=7/6
z=5/6