Infinite Geometric Series

[squance]

My sister can't seem to solve this question from the essential maths textbook and I have no idea as well because I have never seen any of this stuff before...

This is from Exercise 1E question 6.

The first, second and third terms of a geometric sequence are x + 5, x and x + 4 respectively. Find:

a). x
b). the common ratio
c). the difference between the sum to infinity and the sum of the first ten terms

The answers:
a).20
b).4/5
c). 4^10 /5^7


Some help will be muchly appreciated

[Flaming_Arrow]

geometric sequences isn't is the syllabus so your just wasting you time.

[squance]

Ok then. I will tell my sis that. Thanks for the info.

[Mao]

are you sure its x+5 --> x --> x+4 ? it doesn't look too right.

[squance]

are you sure its x+5 --> x --> x+4 ? it doesn't look too right.

I copied it from the Specialist Maths Essential Maths Book.
I wouldn't have a clue if it was a printing error or not because I have never seen one of these questions before in my whole life.

[/0]

The third term is x-4, not that it matters

[squance]

The third term is x-4, not that it matters

Oh shit!
It is x-4.
I just had a third look at that textbook.
Oppsies Im sorry.

So yeah. The terms are x+5, x and x-4.
(I think I need my eyes checked..)

[Mao]

much better. Here's for the interested:

a)

b)

c)

[squance]

Thank you very much
Um, not sure if my eyes are failing on me again, but I don't see the solution to part b of this question