8
8 plus 7 is 15. 15 plus 6 is 21. :)
15 -7 = 8
Yes. 5 + 3 + 7 = 15 and 5 + 7 + 3 = 15
-7 + 15 - 8 = 0
The answer is 8. In the statement "7 plus blank 15," the word "plus" indicates addition. So, the expression can be written as 7 + x = 15, where x is the unknown number. By solving for x, we find that x = 8.
-15
7 + 7+1=15
83
15 - 7 + 6 is 14
8+7 = 15
-15