document.write( "Question 989701: The area of the surface of the swimming pool is 210 square feet. The width is 10 ft. and the length is 9 + d ft. What is the length d? \n" ); document.write( "
Algebra.Com's Answer #609935 by macston(5194)\"\" \"About 
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\n" ); document.write( "L=length; W=width; A=area
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\n" ); document.write( "A=LW
\n" ); document.write( "210=(9+d)(10)
\n" ); document.write( "21=9+d
\n" ); document.write( "12=d
\n" ); document.write( "ANSWER: d=12 feet
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