Answer:
[tex]S_{13}[/tex] = 403
Step-by-step explanation:
the sum to n terms of an arithmetic series is
[tex]S_{n}[/tex] = [tex]\frac{n}{2}[/tex] (a + l) ← a is the first term and l the last term
here a = - 5 and l = 67 , then
[tex]S_{13}[/tex] = [tex]\frac{13}{2}[/tex] (- 5 + 67) = 6.5 × 62 = 403
