空间专门写情话的qq号:救命!数学题!
来源:百度文库 编辑:高考问答 时间:2024/05/29 14:42:57
设x+y+z=A(x+2y+3z)+B(4x+3y+2z)
=(A+4B)x+(2A+3B)y+(3A+2B)z
A+4B=1
2A+3B=1
3A+2B=1
A=1/5,B=1/5
x+y+z
=1/5*(10+15)
=5
设x+y+z=A(x+2y+3z)+B(4x+3y+2z)
=(A+4B)x+(2A+3B)y+(3A+2B)z
A+4B=1
2A+3B=1
3A+2B=1
A=1/5,B=1/5
x+y+z
=1/5*(10+15)
=5