document.write( "Question 1198815: The product of two consecutive integers is 90 less than twice the square of the next larger integer. Find the smaller integer.
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document.write( "A. 6
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document.write( "B. 8
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document.write( "C. 10
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document.write( "D. 12 \n" );
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Algebra.Com's Answer #832459 by math_tutor2020(3835) ![]() You can put this solution on YOUR website! \n" ); document.write( "The first sentence translates to this equation \n" ); document.write( "n(n+1) = 2(n+1)^2-90\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "n = first integer \n" ); document.write( "n+1 = integer right after n\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's solve for n. \n" ); document.write( "n(n+1) = 2(n+1)^2-90 \n" ); document.write( "n^2+n = 2(n^2+2n+1)-90 \n" ); document.write( "n^2+n = 2n^2+4n+2-90 \n" ); document.write( "n^2+n = 2n^2+4n-88 \n" ); document.write( "0 = 2n^2+4n-88-n^2-n \n" ); document.write( "n^2+3n-88 = 0 \n" ); document.write( "(n+11)(n-8) = 0 \n" ); document.write( "n+11 = 0 or n-8 = 0 \n" ); document.write( "n = -11 or n = 8\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If we focus on the positive values only, then n = -11 is ignored.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: Choice B \n" ); document.write( " \n" ); document.write( " |