设X铜,Y铁,Z铝
X+Y+Z=65···········1式
X+Y-Z=1··············2式
X-Y=15·················3式
1式-2式
得Z=32
故X+Y=33················4式
3式+4式
得 X=24
Y=9
设X铜,Y铁,Z铝
X+Y+Z=65···········1式
X+Y-Z=1··············2式
X-Y=15·················3式
1式-2式
得Z=32
故X+Y=33················4式
3式+4式
得 X=24
Y=9