已知满足2x-3y=11-4m和3x+2y=21-5m的x、y也满足x+3y=20-7m,则m的值是 A1 B 2 C 3 D 4

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已知满足2x-3y=11-4m和3x+2y=21-5m的x、y也满足x+3y=20-7m,则m的值是 A1 B 2 C 3 D 4
已知满足2x-3y=11-4m和3x+2y=21-5m的x、y也满足x+3y=20-7m,则m的值是 A1 B 2 C 3 D 4

已知满足2x-3y=11-4m和3x+2y=21-5m的x、y也满足x+3y=20-7m,则m的值是 A1 B 2 C 3 D 4
2x-3y=11-4m ①
3x+2y=21-5m ②
x+3y=20-7m ③
②-①-③,得:y=3m-5 ④
③*2-①,得:9y=29-10m ⑤
解④⑤得:m=2