document.write( "Question 168836This question is from textbook Prentice Hall Algebra 2 with Trigonometry
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document.write( ": Please help me solve this equation: \r
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document.write( "numeric word problem using 3 equations.\r
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document.write( "The sum of three number is 105. The third is 11 less than 10 times the second. Twice the first is 7 more than three times the second. Find the Numbers \n" );
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Algebra.Com's Answer #124492 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! let a = first number. \n" ); document.write( "let b = second number. \n" ); document.write( "let c = third number. \n" ); document.write( "----- \n" ); document.write( "sum of 3 numbers is 105 \n" ); document.write( "a + b + c = 105 \n" ); document.write( "----- \n" ); document.write( "third number is 11 less than 10 times the second. \n" ); document.write( "c = 10*b - 11 \n" ); document.write( "----- \n" ); document.write( "twice the first number is 7 more than 3 times the second. \n" ); document.write( "2*a = 3*b + 7 \n" ); document.write( "a = (3*b+7)/2 \n" ); document.write( "----- \n" ); document.write( "start with: \n" ); document.write( "a + b + c = 105 \n" ); document.write( "substitute for a: \n" ); document.write( "(3*b+7)/2 + b + c = 105 \n" ); document.write( "substitute for c:\" \n" ); document.write( "(3*b+7)/2 + b + 10*b - 11 = 105 \n" ); document.write( "----- \n" ); document.write( "equation is now in terms of b and can be solved. \n" ); document.write( "expand all terms by removing parentheses: \n" ); document.write( "3*b/2 + 7/2 + b + 10*b - 11 = 105 \n" ); document.write( "multiply both sides of equation by 2: \n" ); document.write( "3*b + 7 + 2*b + 20*b - 22 = 210 \n" ); document.write( "combine like terms: \n" ); document.write( "25*b - 15 = 210 \n" ); document.write( "add 15 to both sides of equation: \n" ); document.write( "25*b = 225 \n" ); document.write( "divide both sides of equation by 25: \n" ); document.write( "b = 9 \n" ); document.write( "----- \n" ); document.write( "if b = 9, then: \n" ); document.write( "(3*b+7)/2 = (27+7)/2 = 34/2 = 17 = a \n" ); document.write( "and: \n" ); document.write( "10*b - 11 = 90 - 11 = 79 = c \n" ); document.write( "----- \n" ); document.write( "you have: \n" ); document.write( "a = 17 \n" ); document.write( "b = 9 \n" ); document.write( "c = 79 \n" ); document.write( "total = 105 \n" ); document.write( "----- \n" ); document.write( "total = a + b + c = 79 + 9 + 17 = 88 + 17 = 105 (ok) \n" ); document.write( "----- \n" ); document.write( "c = 10*b - 11 becomes: \n" ); document.write( "c = 10*9 - 11 = 90 - 11 = 79 (ok) \n" ); document.write( "----- \n" ); document.write( "a = (3*b+7)/2 becomes: \n" ); document.write( "a = (3*9+7)/2 = (27+7)/2 = 35/2 = 17 (ok) \n" ); document.write( "-----\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |