document.write( "Question 1153556: Several friends decided to equally share the $525 cost of the set of cookware for a wedding gift. However, before the wedding, 6 more friends joined the others in giving the couple the cookwares. This lowered the contribution of each person by $10. How many friends originally agreed to share of the cost of the cookware? \n" ); document.write( "
Algebra.Com's Answer #775809 by Theo(13342)![]() ![]() You can put this solution on YOUR website! x = number of friends who originally agreed to share the cost. \n" ); document.write( "y = cost per friend. \n" ); document.write( "total cost = 525. \n" ); document.write( "x * y = 525 \n" ); document.write( "when 6 friends join, x becomes x + 6 \n" ); document.write( "when the price is dropped by 10 dollars, y becomes y - 10 \n" ); document.write( "total cost is still 525. \n" ); document.write( "(x + 6) * (y - 10) = 525 \n" ); document.write( "you have two equations that need to be solved simultaneouly. \n" ); document.write( "they are: \n" ); document.write( "x * y = 525 \n" ); document.write( "(x + 6) * (y - 10) = 525 \n" ); document.write( "simplify the second equation to get: \n" ); document.write( "x * y - 10 * x + 6 * y - 60 = 525 \n" ); document.write( "from the first equation, solve for x to get x = 525 / y \n" ); document.write( "in the second equation, replace x with 525 / y to get: \n" ); document.write( "525 / y * y - 10 * 525 / y + 6 * y - 60 = 525 \n" ); document.write( "simplify to get: \n" ); document.write( "525 - 5250 / y + 6 * y - 60 = 525 \n" ); document.write( "multiply both sides of the equation by y to get: \n" ); document.write( "525 * y - 5250 + 6 * y^2 - 60 * y = 525 * y \n" ); document.write( "the 525 * y in both sides of the equaton cancels out and you get: \n" ); document.write( "- 5250 + 6 * y^2 - 60 * y = 0 \n" ); document.write( "reorder the terms in descending order of degree to get: \n" ); document.write( "6 * y^2 - 60 * y - 5250 = 0 \n" ); document.write( "divide both sides of the equation by 6 to get: \n" ); document.write( "y^2 - 10 * y - 875 = 0 \n" ); document.write( "factor this quadratic equation to get: \n" ); document.write( "y = -25 or y = 35. \n" ); document.write( "y has to be positive, so y = 35. \n" ); document.write( "y is the original cost to each friend. \n" ); document.write( "since x * y = 525, then x = 525 / y = 525 / 35 = 15. \n" ); document.write( "the original number of friends was 15 and they each would have to pay 35 dollars each. \n" ); document.write( "6 friends joined for a total of 21 friends. \n" ); document.write( "525 / 21 = 25. \n" ); document.write( "the cost of 35 dollars for each friend dropped from 35 dollars per friend to 25 dollars per friend. \n" ); document.write( "this confirms the solution is correct.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |