Answer:
0+1+2+3+4+5+6=21
Explanation:
Since integers are given as x1, x2, x3, x4, x5, x6, and x7. This means they are consecutive integers divisible by 7.
Thus no matter which 7 consecutive integers are these, their reminders will always be in the order of 0,1,2,3,4,5 & 6.
So their sum will be 0+1+2+3+4+5+6=21.