× + 4 × + 9 12 + × × - 3 × - 6 × = 8

x = 8

1. x+4 = 8+4= 12
2. x+9 = 8+9 =17
3. 12+x = 12+8 =20
4. x-3 = 8-3 =5
5. x-6 = 8-6 =2

x=8
jadi
x+4=8+4=12
x+9=8+9=17
12+x=12+8=19
x-3=8-3=5
x-6=8-6=2
maaf ya kalau salah