Question

hallar la suma de los 8 primeros terminos en la sgte p.g -80;-40,-20

Answer 1

Respuesta:

Explicación paso a paso:

Termino General de P. G.

an = a1 × r^(n-1)

r = 1/2

a4 = -80 × 1/2^(4-1) = -80 × 1/2^(3) = -80 × 1/8 = -10

a5 = -80 × 1/2^(5-1) = -80 × 1/2^(4) = -80 × 1/16 = -5

a6 = -80 × 1/2^(6-1) = -80 × 1/2^(5) = -80 × 1/32 = -2.5

a7 = -80 × 1/2^(7-1) = -80 × 1/2^(6) = -80 × 1/64 = -1.25

a8 = -80 × 1/2^(8-1) = -80 × 1/2^(7) = -80 × 1/128 = -0.625

sumando todos los terminos:

-80 + -40 + -20 + -5 + -2.5 + -1.25 + -0.625 =  -149.375