document.write( "Question 236006: The sum of lisa's age and Ellen's age is 41. five years from now, the sum of their ages will be three times lisa's present age. How old is Lisa?\r
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document.write( "Also to solve this, it has to be either the substitution or elimination method.\r
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document.write( "Thanks. \n" );
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Algebra.Com's Answer #173956 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Try the elimination method \n" ); document.write( ": \n" ); document.write( "Write an equation for each statement: \n" ); document.write( ": \n" ); document.write( "\"The sum of lisa's age and Ellen's age is 41.\" \n" ); document.write( "E + L = 41 \n" ); document.write( ": \n" ); document.write( "\" five years from now, the sum of their ages will be three times lisa's present age.\" \n" ); document.write( "(E+5) + (L+5) = 3L \n" ); document.write( "E + L + 10 = 3L \n" ); document.write( "E + L - 3L = -10 \n" ); document.write( "E - 2L = -10 \n" ); document.write( "Subtract this equation from the 1st equation \n" ); document.write( "E + L = 41 \n" ); document.write( "E -2L = -10 \n" ); document.write( "--------------subtraction eliminates E, find L \n" ); document.write( "3L = 51 \n" ); document.write( "L = \n" ); document.write( "L = 17 yrs is Lisa's present age \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check solution, E = 41 - 17 = 24 \n" ); document.write( "\"five years from now, the sum of their ages will be three times lisa's present age.\" \n" ); document.write( "24 + 5 + 17 + 5 = 3(17) \n" ); document.write( "29 + 22 = 51; confirms our solution \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |