document.write( "Question 1128136: Jeff’s algebra test average will be an 88 if he gets a 72 on the next exam and a 91 if he gets a 90 on the next exam. If all exams are weighted the same, how many exams has Jeff taken so far? \n" ); document.write( "
Algebra.Com's Answer #744599 by stanbon(75887)\"\" \"About 
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Jeff’s algebra test average will be an 88 if he gets a 72 on the next exam and a 91 if he gets a 90 on the next exam. If all exams are weighted the same, how many exams has Jeff taken so far?
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\n" ); document.write( "Let # of tests taken so far be \"n\".
\n" ); document.write( "Let the avg. score on those n tests be \"k\"
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\n" ); document.write( "Total of the scores on the first n tests = kn
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\n" ); document.write( "Equations::
\n" ); document.write( "(72+kn)/(n+1) = 88
\n" ); document.write( "(90+kn)/(n+1) = 91
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\n" ); document.write( "90+kn = 91(n+1)
\n" ); document.write( "72+kn = 88(n+1)
\n" ); document.write( "Subtract to get::
\n" ); document.write( "18 = 3(n-1)
\n" ); document.write( "3n = 21
\n" ); document.write( "n = 7 (# of tests taken so far)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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