2x=15
x=15/2
x=7 1/2
thats all i know
5
4
3
5 + 10 = 15
4 + 8 = 12
3 + 6 = 9
These are at most 15 bust not over 15
6 and above font work because they result in a number above 15
and 2 and below don't work because it is noticeably not close by observation.
7.8m questions
10.5m answers