Question 437569
your getting lost at writing the equation as the length is 6ft more than three times the width is the key to solving this problem.
The perimeter of a rectangle is 2(W)+ 2(L), we are giving perimeter so we can write our first equation...2(W)+2(L0=124
next write out the second equation which is the sentence your stuck at....... L=3(W)+6
 so putting the 2 equations together to get 1 variable we get:
2(W) + 2(3W+6)=124
solve for W=14
solve for L=3 times width add 6
           = 3*14+6
          L = 48

hope that helps!