Question

Find the sum of the first 10 terms of the following sequence. Round to the nearest hundredth if necessary.

Answer 1

S₁₀ = - 838860

Explanation:

the first term a₁ = 4

r =
`(a_(2) )/(a_(1) )` =
`(-16)/(4)` = - 4

substitute these values into
`S_(n)` , then

S₁₀ =
`(4-4(-4)^(10) )/(1-(-4))`

=
`(4-4(1048576))/(1+4)`

=
`(4-4194304)/(5)`

=
`(-4194300)/(5)`

= - 838860