Tolong no 18 caranya

jawab

2/x + 1/y = 2
4/y + 3/z = 5
3/x + 2/z = 3
jumlahkan semua

5/x + 5/y + 5/z = 10
5 ( 1/x + 1/y + 1/z)   = 10
1/x + 1/y + 1/z = 10/5 = 2