document.write( "Question 1122511: find the sum of each of the following inifinite G.P's:
\n" ); document.write( "(a) 1 + 1/3 + 1/9 + 1/27 + +...
\n" ); document.write( "(b) 2/5 + 3/5^2 + 2/5^2 + 3/5^4...
\n" ); document.write( "

Algebra.Com's Answer #738658 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "Th infinite sum of a geometric progression with common ratio between -1 and 1 is

\n" ); document.write( "\"a%2F%281-r%29\"

\n" ); document.write( "where a is the first term and r is the common ratio.

\n" ); document.write( "(a) first term 1; common ratio 1/3. Plug the numbers into the formula.

\n" ); document.write( "(b) I will assume the third term is supposed to be 2/5^3 instead of 2/5^2....

\n" ); document.write( "It's probably easiest to group the terms in pairs. Then the first term is

\n" ); document.write( "\"2%2F5+%2B+3%2F5%5E2+=+%2810%2B3%29%2F5%5E2+=+13%2F25\"

\n" ); document.write( "Grouping the terms in pairs like that then makes the common ratio between the paired terms 1/5^2 = 1/25.

\n" ); document.write( "There are the first term and common ratio. Again plug them into the formula.
\n" ); document.write( "
\n" );