Answer:
S₃₆ = 3402
Step-by-step explanation:
there is a common difference between term in the sequence , that is
12 - 7 = 17 - 12 = 5
this indicates the sequence is arithmetic with sum to n terms
[tex]S_{n}[/tex] = [tex]\frac{n}{2}[/tex] [ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
here a₁ = 7 and d = 5 , then
S₃₆ = [tex]\frac{36}{2}[/tex] [ (2 × 7) + (35 × 5) ]
= 18( 14 + 175)
= 18 × 189
= 3402
