document.write( "Question 164651: The sum of Wilbur’s age and Fred’s age is 20 years.
\n" ); document.write( "Wilbur’s age 1 year from now will be 9 times Fred’s age 1 year ago.
\n" ); document.write( "Find the present age of Wilbur and Fred. \n" ); document.write( "

Algebra.Com's Answer #121327 by jojo14344(1513) $\"\"$ $\"About$

You can put this solution on YOUR website!

\n" ); document.write( " $\"x=Wilburs_Age\"$
\n" ); document.write( " $\"y=Freds_Age\"$
\n" ); document.write( "1st condition: $\"x%2By=20yrs\"$ , EQN 1
\n" ); document.write( "Also we get via EQN 1: $\"x=20-y\"$ , EQN 2
\n" ); document.write( "2nd condition:
\n" ); document.write( "Wilbur's Age One year from now, so $\"x%2B1\"$ ---> will be 9 times as Fred's age a year ago, $\"9%28y-1%29\"$ right?
\n" ); document.write( "Putting into eqn the 2 ages via condition 2:
\n" ); document.write( " $\"x%2B1=9%28y-1%29\"$ , EQN 3
\n" ); document.write( "Subst. EQN 2 in EQN 3:
\n" ); document.write( " $\"20-y%2B1=9y-9\"$
\n" ); document.write( " $\"21%2B9=9y%2By\"$
\n" ); document.write( " $\"30=10y\"$ -----> $\"cross%2830%293%2Fcross%2810%29=cross%2810%29y%2Fcross%2810%29\"$
\n" ); document.write( " $\"y=3yrs\"$ , Fred's Age now
\n" ); document.write( "Via EQN 2
\n" ); document.write( " $\"x=20-3=17yrs\"$ , Wilbur's Age now
\n" ); document.write( "You can check by going to EQN 3, but it's nice going to condition 2 (it's the same anyway):
\n" ); document.write( "Wilbur's Age one year from now, 17+1=18yrs, will be 9 times as Fred's age a year ago, $\"3-1=highlight%282%29\"$ .See highlighted, is 9 times as Wilbur's age, (9*2=18yrs).
\n" ); document.write( "Thank you,
\n" ); document.write( "Jojo\r
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