document.write( "Question 1016403: the 4th term of an A.P is 15 and the 9th term is 35. Find the fifteenth term? \n" ); document.write( "
Algebra.Com's Answer #633118 by MathTherapy(10552)\"\" \"About 
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\n" ); document.write( "the 4th term of an A.P is 15 and the 9th term is 35. Find the fifteenth term?
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4th term
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document.write( "\"a%5Bn%5D+=+a%5B1%5D+%2B+%28n+-+1%29d\"
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document.write( "\"a%5B4%5D+=+a%5B1%5D+%2B+%284+-+1%29d\"
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document.write( "\"15+=+a%5B1%5D+%2B+3d\" ------- eq (i)\r
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document.write( "9th term
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document.write( "\"a%5Bn%5D+=+a%5B1%5D+%2B+%28n+-+1%29d\"
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document.write( "\"a%5B9%5D+=+a%5B1%5D+%2B+%289+-+1%29d\"
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document.write( "\"35+=+a%5B1%5D+%2B+8d\" ------- eq (ii)\r
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document.write( "- 20 = - 5d ------ Subtracting eq (ii) from eq (i)
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document.write( "d, or common difference = \"%28-+20%29%2F%28-+5%29\", or 4
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document.write( "\"35+=+a%5B1%5D+%2B+8%284%29\" ------- Substituting 4 for d in eq (i)
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document.write( "\"35+=+a%5B1%5D+%2B+32\"
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document.write( "\"matrix%281%2C8%2Ca%5B1%5D%2C+or%2C+1%5Est%2C+term%2C+%22=%22%2C+35+-+32%2C+or%2C+3%29\"\r
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document.write( "\"a%5Bn%5D+=+a%5B1%5D+%2B+%28n+-+1%29d\"
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document.write( "\"a%5B15%5D+=+3+%2B+%2815+-+1%294\" ------- Substituting 15 for n, 3 for \"a%5B1%5D\", and 4 for d
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document.write( "\"a%5B15%5D+=+3+%2B+14%284%29\"
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