Answer: pretty sure it's the number you multiply by 4 is 17
Explanation:
when you multiply 4 and 16 you'll get 64 then you subtract 19 and get 45 which is less than 47 so by reasoning if you were to multiply 4 and 17 you'll get 68 then you subtract 19 from 68 and you should get 49 ( you didn't include how much greater than 47 the number should be but the safest bet would be to use 17)