document.write( "Question 1104869: Inverse Variation:\r
\n" ); document.write( "\n" ); document.write( "The force of attraction (F) between two opposite electrical charges varies inversely as the square of the distance between them. If F=18 when d=10, find F when d=15. \r
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Algebra.Com's Answer #719572 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
inverse variation formula is y = k/x.\r
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\n" ); document.write( "\n" ); document.write( "let F = y and let d^2 = x and you get F = k/d^2\r
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\n" ); document.write( "\n" ); document.write( "F = 18 when d = 10, therefore the equation becomes 18 = k/100.\r
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\n" ); document.write( "\n" ); document.write( "solve for k to get k = 100*18 = 1800.\r
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\n" ); document.write( "\n" ); document.write( "k is the constant of variation, so k will always remain at 1800 in this equation.\r
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\n" ); document.write( "\n" ); document.write( "you want to find F when d = 15.\r
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\n" ); document.write( "\n" ); document.write( "formula becomes F = 1800 / 15^2.\r
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\n" ); document.write( "\n" ); document.write( "solve for F to get F = 8.\r
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