document.write( "Question 1150818: By selling a dress for $5500, a woman lost 30%. For how much should she have sold it to gain 30% \n" ); document.write( "
Algebra.Com's Answer #772312 by Theo(13342)![]() ![]() You can put this solution on YOUR website! she sold the dress for 5500 and lost 30%.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let c equal the cost of the dress. \n" ); document.write( "let s equal the price she sold it at. \n" ); document.write( "let p equal the profit she sold it at. \n" ); document.write( "a negative profit is the same as a loss.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "equation to use is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "p = (s - c) / c \n" ); document.write( "when p = -30%, then p = -.30 \n" ); document.write( "you use the rate, not the percent. \n" ); document.write( "this becomes: \n" ); document.write( "-.30 = (5500 - c) / c \n" ); document.write( "multiply both sides of this equation by c to get: \n" ); document.write( "-.30 * c = 5500 - c \n" ); document.write( "add c to both sides of this equation to get: \n" ); document.write( "c - .30 * c = 5500 \n" ); document.write( "combine like terms to get: \n" ); document.write( ".70 * c = 5500 \n" ); document.write( "solve for c to get: \n" ); document.write( "c = 5500 / .7 = 7857.142857\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "to confirm, take 30% off 7857.142857 and you get 5500. \n" ); document.write( "5500 is what it sold at when 30% was lost.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "to gain 30%, use the same equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "p = (s - c) / c\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when p = 30% and when c = 7857.142857, then the equation becomes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( ".3 = (s - 7857.142857) / 7857.142857 \n" ); document.write( "once again, you use the rate, not the percent. \n" ); document.write( "multiply both sides by 7857.142857 to get: \n" ); document.write( ".3 * 7857.142857 = s - 7857.142857 \n" ); document.write( "add 7857.142857 to both sides of the equation to get: \n" ); document.write( ".3 * 7857.142857 + 7857.142857 = s \n" ); document.write( "solve for s to get: \n" ); document.write( "s = 10214.28571\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "to confirm, add 30% to 7857.142857 and you get 10214.28571 \n" ); document.write( "this is what it sells at when 30% is gained.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |