document.write( "Question 250626: WHAT IS THE 10TH TERM OF THE GEOMETRIC SEQUENCE 64,-32,16,8??? \n" ); document.write( "
Algebra.Com's Answer #184812 by drk(1908)\"\" \"About 
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We have to find a pattern. First, geometric sequences have the following formula:
\n" ); document.write( "(I) \"t%28n%29+=+a%28r%29%5E%28n-1%29\"
\n" ); document.write( "Here are the numbers: 64, -32, 16, 8.
\n" ); document.write( "t(1) = 64
\n" ); document.write( "t(2) = -32
\n" ); document.write( "t(3) = 16
\n" ); document.write( "t(4) = -8
\n" ); document.write( "Put t(1) into (i) and we get
\n" ); document.write( "64 = ar^(1-1)
\n" ); document.write( "** 64 = a **.
\n" ); document.write( "Put t(2) = -32 into (i)and include a = 64. We get
\n" ); document.write( "-32 = 64r^(2-1)
\n" ); document.write( "-32 = 64r^1
\n" ); document.write( "divide by 64 and we get
\n" ); document.write( "** r = -1/2 **.
\n" ); document.write( "We know a and r. Now we write the formula as
\n" ); document.write( "\"T%28n%29=+64%28-1%2F2%29%5E%28n-1%29\"
\n" ); document.write( "We want the 10-th term, or n = 10. SO,
\n" ); document.write( "\"t%2810%29+=+64%28-1%2F2%29%5E%2810-1%29\"
\n" ); document.write( "\"t%2810%29+=+64%282%29%5E%28-9%29\" = 64/512 = .125 \n" ); document.write( "
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