学霸降临

{x+2y+z=72x-y+3z=73x+y+2z=18}组:{x+2y+z=7 2x-y+3z=7②3x+y+2z=18③}

.解：①+②×2得：5x+7z=21④ ②+③得：x+z=5⑤ 联立④、⑤得： {5x+7z=21 x+z=5} 利用二元一次方程解法解得： {x=7，z=-2} 把x=7，z=-2代入①，可解得y=1 所以原方程组的解为： {x=7，y=1，z=-2}

不敢当，不敢当。

额……你夸的我都不好意思了。

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Forsurelythere'sslways