document.write( "Question 349039: In 7 years Deac will be twice as old as Irina. Four
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document.write( "years ago he was three times as old as Irina was
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document.write( "then. How old are each of them now? \n" );
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Algebra.Com's Answer #249482 by haileytucki(390)![]() ![]() You can put this solution on YOUR website! \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A + 7 = 2(B+7) \r \n" ); document.write( "\n" ); document.write( "A + 7 = 2B + 14 \r \n" ); document.write( "\n" ); document.write( "A - 2B = 7 \r \n" ); document.write( "\n" ); document.write( "and\r \n" ); document.write( "\n" ); document.write( "A - 4 = 3(B-4) \r \n" ); document.write( "\n" ); document.write( "A - 4 = 3B - 12 \r \n" ); document.write( "\n" ); document.write( "3B - A = 8\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "adding the two equations together:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "[A - 2B] + (3B - A) = [7] + (8) \n" ); document.write( "[A-2B]+(3B-A)=[7]+(8)\r \n" ); document.write( "\n" ); document.write( "Remove the parentheses that are not needed from the expression. \n" ); document.write( "A-2B+3B-A=[7]+(8)\r \n" ); document.write( "\n" ); document.write( "Since A and -A are like terms, add -A to A to get 0. \n" ); document.write( "0-2B+3B=[7]+(8)\r \n" ); document.write( "\n" ); document.write( "Since -2B and 3B are like terms, subtract 3B from -2B to get B. \n" ); document.write( "B=[7]+(8)\r \n" ); document.write( "\n" ); document.write( "Remove the parentheses that are not needed from the expression. \n" ); document.write( "B=7+8\r \n" ); document.write( "\n" ); document.write( "Add 8 to 7 to get 15. \n" ); document.write( "B=15 \n" ); document.write( "Now we have B=115, we substitute it into the original equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A-2(15)=7\r \n" ); document.write( "\n" ); document.write( "Multiply -2 by each term inside the parentheses. \n" ); document.write( "A-30=7\r \n" ); document.write( "\n" ); document.write( "Since -30 does not contain the variable to solve for, move it to the right-hand side of the equation by adding 30 to both sides. \n" ); document.write( "A=30+7\r \n" ); document.write( "\n" ); document.write( "Add 7 to 30 to get 37. \n" ); document.write( "A=37\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " Deac is 37 and Irina is 15. \n" ); document.write( " \n" ); document.write( " |