Answer:
Step-by-step explanation:
Let

where we assume |r| < 1. Multiplying on both sides by r gives

and subtracting this from
gives

As n → ∞, the exponential term will converge to 0, and the partial sums
will converge to

Now, we're given


We must have |r| < 1 since both sums converge, so


Solving for r by substitution, we have


Recalling the difference of squares identity, we have

We've already confirmed r ≠ 1, so we can simplify this to

It follows that

and so the sum we want is

which doesn't appear to be either of the given answer choices. Are you sure there isn't a typo somewhere?
Answer:

Step-by-step explanation:

![\textsf{x=1/2[(4x+5)-50]}](https://tex.z-dn.net/?f=%5Ctextsf%7Bx%3D1%2F2%5B%284x%2B5%29-50%5D%7D)







Answer:
1821.25
Step-by-step explanation:
= 1821.25