document.write( "Question 868850: The surface area of a ballon varies directly as the square of its radius. The Area is 325 square inches when the radious is 5 inches. What is the surface area when the radius is 9 inches? \n" ); document.write( "
Algebra.Com's Answer #523861 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
\"+S+%28alpha%29+r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"S=kr%5E2\"\r
\n" ); document.write( "\n" ); document.write( "area 325
\n" ); document.write( "r=5\r
\n" ); document.write( "\n" ); document.write( "325 =k *5^2\r
\n" ); document.write( "\n" ); document.write( "325/25 = k
\n" ); document.write( "13=k\r
\n" ); document.write( "\n" ); document.write( "r=9\r
\n" ); document.write( "\n" ); document.write( "S= 13*9^2\r
\n" ); document.write( "\n" ); document.write( "S= 1053 sq.units
\n" ); document.write( "
\n" );