document.write( "Question 259071: A square's side is increased by 10 yards, which corresponds to an increase in the area by 400 square yards. How many yards is the side of the initial square? \n" ); document.write( "
Algebra.Com's Answer #190774 by ankor@dixie-net.com(22740)\"\" \"About 
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A square's side is increased by 10 yards, which corresponds to an increase in the area by 400 square yards.
\n" ); document.write( "How many yards is the side of the initial square?
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\n" ); document.write( "Let x = side of the original square
\n" ); document.write( "then
\n" ); document.write( "(x+10) = side of the larger square
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\n" ); document.write( "Large area - small area = 400 sq/yd
\n" ); document.write( "(x+10)^2 - x^2 = 400
\n" ); document.write( "FOIL
\n" ); document.write( "x^2 + 20x + 100 - x^2 = 400
\n" ); document.write( "20x = 400 - 100
\n" ); document.write( "20x = 300
\n" ); document.write( "x = \"300%2F20\"
\n" ); document.write( "x = 15 yds is the original square
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\n" ); document.write( ":
\n" ); document.write( "Check it:
\n" ); document.write( "25^2 - 15^2 =
\n" ); document.write( "625 - 225 = 400 \n" ); document.write( "
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