Respuesta :

Answer:

- 1050

Step-by-step explanation:

The sum to n terms of an arithmetic sequence is

[tex]S_{n}[/tex] = [tex]\frac{n}{2}[/tex] [ 2a₁ + (n - 1)d ], thus

[tex]S_{20}[/tex] = [tex]\frac{20}{2}[/tex] [ (2 × - 74) + (19 × - 3) ]

= 10 ( - 148 - 57) = 10 × - 105 = - 1050