How do you evaluate sigma notation equations?

Question

anonymous · Answer

$$\sum_{n = 2}^{10} 25(0.3)^{n + 1}$$

anonymous · Answer

@kohai @xDre15 @mathmath333

anonymous · Answer

@Blu-Girl @Queen_Bee1 @rockstar349002 @tester97 @flvsucks

anonymous · Answer

@nerdguy2535 Please help :)

anonymous · Answer

There is not a general way to evaluate all sigma notation formulas. There are specific types that do have formulas though. This one is whats called a Geometric series. It is close to the form: $$\sum _{k=0}^ncr^k$$which has the formula: $$\sum _{k=0}^ncr^k=c\left(\frac{r^{n+1}-1}{r-1}\right)$$

anonymous · Answer

remunsum!!!!!

anonymous · Answer

You need to manipulate your sum a little to get it into the right form to use the formula.

anonymous · Answer

Okay @nerdguy2535 if it's a geometric sequence, that means simplification can only occur if the bases are equal. I'm not sure what to do from here to manipulate it...