Question

Please help me with 12 and 13!

Answer 1

12) (divide by 3)
x = 21, y = 7
x = 27, y = 9

13) (multiply by 8)
a = 6, b = 48
a = 8, b = 64

Answer 2

12. 7 and 9. Here's why- 3x3=9, 3x5=15, 3x6=18, 3x7=21, 3x9=27. Everything is divisible by 3. 

13. I'm not sure about 13 but i hope I could help with 12. Hopefully someone can comment on this and figure out 13 for you.