34
15+6 is 21. 13 + what is 21? 21 - 13 is 8 Eight
13 + 21 - 7 + 12 = 15
n + 13 = 21. n = 21 - 13
-21
5
4x+13 = 21 4x = 21-13 4x = 8 x = 2
-13 + 34 = 21
273 13+8 = 21 and 13*21 = 273
basically you asked what -28+21 which equals -7
25 + 16 - 13 - 21 = 7
It is -34 + v.
5