document.write( "Question 792153: If today is my birthday, and my age fifteen years ago is the square of my age fifteen years from now, what is my age? \n" ); document.write( "
Algebra.Com's Answer #479939 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "I think it should read:
\n" ); document.write( "my age fifteen years ago squared, is my age fifteen years from now,
\n" ); document.write( " what is my age?
\n" ); document.write( ":
\n" ); document.write( "Let a = your present age
\n" ); document.write( "(a-15)^2 = (a+15)
\n" ); document.write( "a^2 - 30a + 225 = a + 15
\n" ); document.write( "a^2 - 30a - a + 225 - 15 = 0
\n" ); document.write( "a^2 - 31a + 210 = 0
\n" ); document.write( "Factors to
\n" ); document.write( "(a-10)(a-21) = 0
\n" ); document.write( "Two solutions
\n" ); document.write( "a = 10
\n" ); document.write( "a = 21, this is the only solution that makes sense
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check
\n" ); document.write( "(21-15)^2 = 36
\n" ); document.write( "21 + 15 = 36 \n" ); document.write( "
\n" );