document.write( "Question 132927: If the numerator and denominator of a fraction are both decreased by three, the fraction becomes 4\5. If the numerator and denominator are both increased by three, the fraction becomes 7\8.\r
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document.write( "1. Write down two equations from the statement?
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document.write( "2. Solve the equations simultaneously to get the original fraction. \n" );
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Algebra.Com's Answer #97133 by ptaylor(2198)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Let x=numerator of original fraction \n" ); document.write( "And let y=denominator of original fraction\r \n" ); document.write( "\n" ); document.write( "We are told that: \n" ); document.write( "(x-3)/(y-3)=4/5 multiply each side by 5(y-3) \n" ); document.write( "5(x-3)=4(y-3) get rid of parens \n" ); document.write( "5x-15=4y-12 subtract 4y from and add 15 to both sides \n" ); document.write( "5x-15+15-4y=4y-4y-12+15 collect like terms \n" ); document.write( "5x-4y=3---------------------------------------------eq1\r \n" ); document.write( "\n" ); document.write( "We are also told that: \n" ); document.write( "(x+3)/(y+3)=7/8 multiply each side by 8(y+3) \n" ); document.write( "8(x+3)=7(y+3) get rid of parens \n" ); document.write( "8x+24=7y+21 subtract 7y and also 24 from both sides \n" ); document.write( "8x-7y+24-24=7y-7y+21-24 collect like terms\r \n" ); document.write( "\n" ); document.write( "8x-7y=-3------------------------------------------eq2 \n" ); document.write( "Multiply each term in eq1 by 8 \n" ); document.write( "40x-32y=24-----------------------------------eq1a \n" ); document.write( "Multiply each term in eq2 by 5 \n" ); document.write( "40x-35y=-15-------------------------------------eq2a\r \n" ); document.write( "\n" ); document.write( "subtract eq1a from eq2a\r \n" ); document.write( "\n" ); document.write( "-3y=-39 divide both sides by -3 \n" ); document.write( "y=13--------------------------------------denominator of original fraction\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute y=13 into eq1 \n" ); document.write( "5x-4*13=3 \n" ); document.write( "5x-52=3 add 52 to both sides \n" ); document.write( "5x-52+52=3+52 collect like terms \n" ); document.write( "5x=55 divide both sides by 5 \n" ); document.write( "x=11-------------------------------------numerator of original fraction\r \n" ); document.write( "\n" ); document.write( "CK \n" ); document.write( "(11-3)/(13-3)=4/5 \n" ); document.write( "8/10=4/5 \n" ); document.write( "4/5=4/5 \n" ); document.write( "also \n" ); document.write( "(11+3)/(13+3)=7/8 \n" ); document.write( "14/16=7/8 \n" ); document.write( "7/8=7/8\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Hope this helps----ptaylor \n" ); document.write( " |