
Probability and Statistics Basic Probability and Statistics Math Forum 
 LinkBack  Thread Tools  Display Modes 
March 7th, 2017, 09:27 AM  #1 
Newbie Joined: Mar 2017 From: Paris Posts: 3 Thanks: 0  Sum equation problem
Hi everyone. I have an equation to solve  don't know how to proceed. $\displaystyle \sum_{i=0}^n(1.1*x)^n=y$ x and y are known values. I need to figure out the value of n. Any tips out there? Thanks 
March 7th, 2017, 09:48 AM  #2  
Senior Member Joined: Sep 2015 From: CA Posts: 1,107 Thanks: 578  Quote:
solving this should be pretty straightforward now.  
March 7th, 2017, 11:11 AM  #3 
Newbie Joined: Mar 2017 From: Paris Posts: 3 Thanks: 0 
Thanks Romsek ! I can now extract n with a logx. Easy. 
March 8th, 2017, 02:26 PM  #4 
Newbie Joined: Mar 2017 From: Paris Posts: 3 Thanks: 0 
Conversely, what about if I am interesting in figure out what is the value of x, knowing all the other variables? This is equivalent to the following: let's say I have : $\displaystyle x^0+x^1+x²+x³=17$ How can I calculate x? If I use the same above formula, I have an equation with x^(n+1)+ax+c. Thanks! 

Tags 
equation, problem, sum 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Equation Problem  marcus2015  Algebra  2  February 18th, 2015 04:25 PM 
having problem with equation  chuackl  Linear Algebra  5  May 30th, 2014 12:02 AM 
Equation problem.  jiasyuen  Elementary Math  5  January 23rd, 2014 10:05 AM 
Equation Problem..?!  p1xel  Algebra  5  June 5th, 2012 12:31 PM 
Dif equation problem  FreaKariDunk  Applied Math  8  April 25th, 2012 07:25 AM 