9+12 = 21
9 + 12 = 21
3 + 9 = 12
simply 9
the sum of 1 plus 9 is 10 because 1+9
8. To find 'the sum of' something, is just to add them together really. Eg - The sum of 9 + 3 = 12.
-23 is the sum of -32 and 9
They sum up to 15
It is: 12+9 = 21
4/3 = 12/9 then 2/9 + 12/9 = 14/9 = 1 and 5/9
12/10+2=12
12
8/9