作业帮Help!Help!Help me!已知满足2x-3y=11-4m和3x+2y=21-5m的x,y满足x+3y=20-7m,求m的值.
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Help!Help!Help me!已知满足2x-3y=11-4m和3x+2y=21-5m的x,y满足x+3y=20-7m,求m的值.
Help!Help!Help me!
已知满足2x-3y=11-4m和3x+2y=21-5m的x,y满足x+3y=20-7m,求m的值.
Help!Help!Help me!已知满足2x-3y=11-4m和3x+2y=21-5m的x,y满足x+3y=20-7m,求m的值.
将三个已经条件标号
2x-3y=11-4m-------(1)
3x+2y=21-5m-------(2)
x+3y=20-7m------(3)
由1,3式得3x=31-11m-----(4)
1,2式得13x=85-23m-----(5)
再由4,5两个式子,消去x得m=2