document.write( "Question 1162695: I am needing help in setting up this equation:
\n" );
document.write( "A 96 ft rope is cut into 4 pieces. The second piece is 6 less than twice as long as the first piece. The third piece is 5 feet greater than the first piece. AndThe fourth is half as long as the second piece. How long is the fourth piece? \n" );
document.write( "
Algebra.Com's Answer #786519 by Theo(13342)![]() ![]() You can put this solution on YOUR website! let the length of each piece be a, b, c, d. \n" ); document.write( "you get: \n" ); document.write( "a + b + c + d = 96 \n" ); document.write( "you get the following additional equations based on the problem statement. \n" ); document.write( "b = 2a - 6 \n" ); document.write( "c = a + 5 \n" ); document.write( "d = b/2 \n" ); document.write( "the trick is to reduce the number of variables to 1. \n" ); document.write( "then the problem can be solved. \n" ); document.write( "we'll try to make everything in terms of a. \n" ); document.write( "d = b/2 is not in terms of a, but we know that b = 2a - 6 \n" ); document.write( "replace b in the equation of d = b/2 to get d = (2a - 6) / 2 \n" ); document.write( "now you have everything in terms of a. \n" ); document.write( "you have: \n" ); document.write( "b = 2a - 6 \n" ); document.write( "c = a + 5 \n" ); document.write( "d = (2a - 6) / 2 \n" ); document.write( "a + b + c + d = 96 becomes: \n" ); document.write( "a + (2a - 6) + (a + 5) + (2a - 6) / 2 = 96 \n" ); document.write( "simplify to get: \n" ); document.write( "a + 2a - 6 + a + 5 + 2a/2 - 6/2 = 96 \n" ); document.write( "simplify further to get: \n" ); document.write( "a + 2a - 6 + a + 5 + a - 3 = 96 \n" ); document.write( "combine like terms to get: \n" ); document.write( "5a - 4 = 96 \n" ); document.write( "add 4 to both sides of the equation to get: \n" ); document.write( "5a = 100 \n" ); document.write( "solve for a to get: \n" ); document.write( "a = 100 / 5 = 20 \n" ); document.write( "b = 2a - 6 = 40 - 6 = 34 \n" ); document.write( "c = a + 5 = 25 \n" ); document.write( "d = b / 2 = 17 \n" ); document.write( "a + b + c + d = 20 + 34 + 25 + 17 = 96 \n" ); document.write( "solution is confirmed to be good. \n" ); document.write( "solution is the fourth piece (piece d) is 17 feet in length. \n" ); document.write( " \n" ); document.write( " |