document.write( "Question 496693: ela is twice as old as her friend lilia. lilia is 7 years older than raquel. ten years ago, ela was three times as old as raquel. how old is lilia now ? \n" ); document.write( "
Algebra.Com's Answer #336525 by Edwin McCravy(20056)![]() ![]() You can put this solution on YOUR website! ela is twice as old as her friend lilia. lilia is 7 years older than raquel. ten years ago, ela was three times as old as raquel. how old is lilia now ?\r \n" ); document.write( "\n" ); document.write( "ela is twice as old as her friend lilia. \n" ); document.write( " \r\n" ); document.write( "E = 2L\r\n" ); document.write( " \n" ); document.write( "Lilia is 7 years older than raquel. \n" ); document.write( " \r\n" ); document.write( "L = R + 7\r\n" ); document.write( " \n" ); document.write( "ten years ago, ela was three times as old as raquel [WAS THEN]. \n" ); document.write( " \r\n" ); document.write( "E - 10 = 3(R - 10)\r\n" ); document.write( "\r\n" ); document.write( "So you have the system of three equations in three unknowns:\r\n" ); document.write( "\r\n" ); document.write( "ìE = 2L\r\n" ); document.write( "íL = R + 7\r\n" ); document.write( "îE - 10 = 3(R - 10)\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Can you solve that system of equations? If not, post again \r\n" ); document.write( "asking how.\r\n" ); document.write( "\r\n" ); document.write( "Solution: Ella is 82, Lelia is 41 and Raquel is 34.\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Checking:\r\n" ); document.write( "\r\n" ); document.write( "Ela, who is 84, is twice as old as her friend Lilia, who is 41. That checks.\r\n" ); document.write( "\r\n" ); document.write( "Lilia, who is 41, is 7 years older than Raquel, who is 34. That checks. \r\n" ); document.write( "\r\n" ); document.write( "Ten years ago, Ela was 72, which is three times as old as Raquel was then,\r\n" ); document.write( "for Raquel was 24 then, and 3×24 = 72. So that checks so we have the \r\n" ); document.write( "correct solution.\r\n" ); document.write( "\r\n" ); document.write( "Edwin\n" ); document.write( " |