( x + 1/y )( y + 1/z )=1
→xy + 1 + x/z + 1/yz = 1
→ xyz + x + 1/y =0
→ xyz + 1 = 0
→ xyz = -1
xyz + 3 = -1 + 3 = 2
偷吃步
令X=1/2,則Y要=2
若Y=2則Z=-1
所以XYZ+3=-1+3=2
50. 令 ,試求 xyz + 3=? (A)2 (B..-阿摩線上測驗