(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

If

[tex]1 + 2x + 4x^2 + ... = \frac{3}{4}[/tex]

find the value of x. [Edit: Forgot to ask the question]

2. Relevant equations

[tex]S_n = \frac{a(1 - r^n)}{1 - r} [/tex]

[tex] t_n = ar^{n-1} [/tex]

3. The attempt at a solution

a = 1

r = 2x

I try to solve [tex]S_n[/tex] and end up with

[tex]2x^n = \frac{6x - 7}{4}[/tex]

which I can't solve.

I try to solve by equating t2 and t3 and getting x = (1/2). Which is wrong.

Any help appreciated.

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# Finding x in a geometric progression, given the sum.

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