document.write( "Question 221033: Four years ago Katie was twice as old as Anne was then. in 6 years, Anne will be the same age that katie is now. How old is each now ?\r
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document.write( "I have two equattions of Katie= X, y= Anne
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document.write( "2X-4= y
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document.write( "x+6 = 2y - 4 \n" );
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Algebra.Com's Answer #165829 by drj(1380)![]() ![]() You can put this solution on YOUR website! Four years ago Katie was twice as old as Anne was then. In 6 years, Anne will be the same age that Katie is now. How old is each now ?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I have two equations of Katie= X, y= Anne\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2X-4= y \n" ); document.write( "x+6 = 2y - 4\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "You're in the right track and good try in getting two linear equations....I'll check your work by the following steps.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 1. Let x be Katie's age and y be Anne's age.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 2. Let x-4 be Katie's age 4 years ago and y-4 be Anne's age four years ago.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 3. Then, x-4= 2(y-4) since four years ago Katie was twice as old as Anne was then. Simplifying yields x-2y=-4\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 4. Let y+6 be the age of Anne.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 5. Then y+6=x since in 6 years, Anne will be the same age that Katie is now. Simplifying yields x-y=6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 6. The system of equations from Steps 3 and 5 are\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x-2y=-4 Equation A \n" ); document.write( "x-y-=6 Equation B\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "OR multiplying Equation B by -1 yields\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x-2y=-4 Equation A \n" ); document.write( "-x+y=-6 Equation B1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Adding yields\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x-x-2y+y=-4-6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "or y=10 and x=10+6=16\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substituting x=16 and y=10, into Steps 3 and 5 yields true statements.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 7. ANSWER: Kate is 16 years old and Anne is 10 years old.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I hope the above steps were helpful.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Good luck in your studies!\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Respectfully, \n" ); document.write( "Dr J \n" ); document.write( " |