If b/7 + (b^2)/(7^2) + (b^3)/(7^3) + (b^4)/(7^4) ... = 7
What is b?
By geometric series, b = 50/7.
Using the sum of G.S. formula, we have
\(\dfrac{\dfrac b7}{1 - \dfrac b7} = 7\\ \dfrac b7 = 7 - b\\ \dfrac {8b}7 = 7\\ b = \dfrac{49}8\)
