document.write( "Question 1149530: Antonette age is 3 years older than her sister. 6 years ago her sister is 4 times antonette age. How old is antonette? \n" ); document.write( "
Algebra.Com's Answer #770870 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "The statement of the problem is faulty; it says now Antonette is older and 6 years ago her sister was older.

\n" ); document.write( "I will ignore that and solve the problem as it was probably intended -- with Antonette older.

\n" ); document.write( "Using formal algebra... which I will assume is what you are learning to do by asking this question....

\n" ); document.write( "Let the sister's age be x
\n" ); document.write( "Then Antonette's age is x+3

\n" ); document.write( "Then 6 years ago the sister's age was x-6, and Antonette's age was (x+3)-6 = x-3.

\n" ); document.write( "Then, since 6 years ago Antonette was 4 times as old as her sister,

\n" ); document.write( "\"x-3+=+4%28x-6%29\"
\n" ); document.write( "\"x-3+=+4x-24\"
\n" ); document.write( "\"21+=+3x\"
\n" ); document.write( "\"x+=+7\"

\n" ); document.write( "ANSWER: Antonette's age is x+3 = 10 years

\n" ); document.write( "CHECK: 6 years ago, Antonette was 10-6 = 4 years old and her sister was 7-6 = 1 year old; Antonette was 4 times as old as her sister.

\n" ); document.write( "Note that, if a formal algebraic solution is not required, the question can be answered quickly with a little logical reasoning and simple arithmetic.

\n" ); document.write( "If the difference between their ages is 3 years, then when Antonette was 4 times as old as her sister, their ages had to be 4 and 1.

\n" ); document.write( "And since that was 6 years ago, their ages now are 10 and 7.

\n" ); document.write( "While knowing how to solve problems like this with formal algebra is important, solving them using logical reasoning is also good mental exercise.

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