Relax

Respuesta :

Answer: -1280

------------------------

Work Shown:

a(n) = a*r^(n-1)
a(n) = -10*2^(n-1)
a(8) = -10*2^(8-1)
a(8) = -10*2^7
a(8) = -10*128
a(8) = -1280