document.write( "Question 127362: Frida is five years older than Fredelyn. In three years the product of her age and Fredelyn's age five years ago will be 9o years. zFind their present ages. \n" ); document.write( "
Algebra.Com's Answer #93316 by solver91311(24713)\"\" \"About 
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Frida's current age is x and Fredelyn's current age is y.\r
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\n" ); document.write( "\n" ); document.write( "The first thing we know is that \"x=y%2B5\"\r
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\n" ); document.write( "\n" ); document.write( "Three years from now Frida will be \"x%2B3\" and five years ago, Fredelyn was \"y-5\" and we know that the product of these two values is 90, so:\r
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\n" ); document.write( "\n" ); document.write( "\"%28x%2B3%29%28y-5%29=90\".\r
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\n" ); document.write( "\n" ); document.write( "Substitute the expression for x in terms of y from the first equation into the second equation:
\n" ); document.write( "\"%28%28y%2B5%29%2B3%29%28y-5%29=90\"\r
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\n" ); document.write( "\n" ); document.write( "Simplify, expand, and put into standard form:
\n" ); document.write( "\"%28y%2B8%29%28y-5%29=90\"
\n" ); document.write( "\"y%5E2%2B3y-40=90\"
\n" ); document.write( "\"y%5E2%2B3y-130=0\"\r
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\n" ); document.write( "\n" ); document.write( "\"-130=%28-10%29%2813%29\" and \"3=-10%2B13\", so:\r
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\n" ); document.write( "\n" ); document.write( "\"%28y-10%29%28y%2B13%29=0\", hence Fredelyn is either 10 or -13 years old. Since a negative number for the age of a person is absurd, exclude this root. Fredelyn is therefore 10 years old.\r
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\n" ); document.write( "\n" ); document.write( "From equation 1: Frida is \"10%2B5=15\" years old.\r
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\n" ); document.write( "\n" ); document.write( "Check:\r
\n" ); document.write( "\n" ); document.write( "\"%2815%2B3%29%2810-5%29=18%2A5=90\" answer checks.
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