document.write( "Question 333508: The difference of the present ages of two brothers is 4 years,5years ago,if the product of their ages was 96,find their ages. \n" ); document.write( "

Algebra.Com's Answer #238975 by mananth(16946) $\"\"$ $\"About$

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let elder brother's age be x
\n" ); document.write( "the youger brother's age be y
\n" ); document.write( "..
\n" ); document.write( "x-y=4
\n" ); document.write( "x=y+4
\n" ); document.write( "..
\n" ); document.write( "five years ago they were x-5
\n" ); document.write( "& y-5
\n" ); document.write( "..
\n" ); document.write( "(x-5)(y-5)=96
\n" ); document.write( "xy-5x-5y+25=96
\n" ); document.write( "xy-5x-5y=96-25
\n" ); document.write( "xy-5x-5y=71
\n" ); document.write( "plug the value of x
\n" ); document.write( "(y+4)y-5(y+4)-5y=71
\n" ); document.write( "y^2+4y -5y-20-5y=71
\n" ); document.write( "y^2-6y-91=0\r
\n" ); document.write( "\n" ); document.write( "y^2-13y+7y-91=0
\n" ); document.write( "y(y-13)+7(y-13)=0
\n" ); document.write( "(y-13)(y+7)=0
\n" ); document.write( "y =13 ignore negative value.
\n" ); document.write( "x=y+4
\n" ); document.write( "x=13+14=17
\n" ); document.write( "The ages are 13 , 17 years
\n" ); document.write( "CHECK
\n" ); document.write( "(17-5)(13-5)=96 \n" ); document.write( "

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