Question

D=1-4+7-10+....+307-310+313

Answer 1

D=1-4+7-10+....+307-310+313

=(1-4)+(7-10)+....+(307-310)+313

=-3-3-....-3+313

=-3.104+313

=-312+313

=1

Answer 2

D =(1-4)+(7-10)+...+(307-310)+313

D =(-3)x104+313

D =-312+313

D =1