the number is 11
21
It could be: (4*11.25)+7 = 52
It is 9*(n + 7)
The answer is 7. Explanation: x+2x=21 therefore 3x=21 so it must be 7
4(7+V)
That number would be 3
the number is 11
It is: 4 times (7+1) = 32
(15+7) +99
21
18
7
It could be: (4*11.25)+7 = 52
It is 9*(n + 7)
The number is 7.
If you add a single number - in this case minus seven - the "sum" is the number itself.