Question

sum_{i=1}^{B}C
Rewrite the sume 4+4^2+4^3+...+4^n.
What is B and what is C?

Answer 1

\[\sum_{i=1}^b C\]?

Answer 2

not really clear what you wrote, but in this case it looks like
\[B=n\] and \[C=4^i\]

Answer 3

That's exactly what I wrote. If it was the same thing but the numbers were:
z+2z^2+3z^3+4z^4+5z^5+6z^6
Would B be 6 and C be i^2?