已知{2x-5y=0 则x+y+z/2y= x-6y+3z=0

问题描述:

已知{2x-5y=0 则x+y+z/2y= x-6y+3z=0

2x-5y=0 x=5y/2①
x-6y+3z=0 ②
①代入②得 5y/2-6y+3z=0 即 3z=7y/2,z=7y/6
∴(x+y+z)/2y=(5y/2+y+7y/6)/y=(5/2+1+7/6)y/y=14/3