(1)*2: 4X+10Y+8Z=30.(3)
(3)+(2):11X+11Y+11Z=44...(4)
(4)/11:X+Y+Z=4
答案就是4
已知：2X＋5Y＋4Z＝15,7X＋Y＋3Z＝14．求X＋Y＋Z的值．
3个回答
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