Two lengths of stereo wire total 32.5 ft. one length is 2.9ft longer than the other. how long is each length of wire?

The length of the long one is half the total plus half the difference:
  (1/2)(32.5 +2.9) ft = 17.7 ft

The length of the short one is 2.9 ft less:
  17.7 ft -2.9 ft = 14.8 ft.


If you like, you can write an equation for the length of the long wire (L).
  L +(L -2.9) = 32.5 . . . . . . . total length of both wires
  2L = 32.5 +2.9 . . . . . . . . . simplify, add 2.9
  L = (1/2)(32.5 +2.9) . . . . . looks a lot like the solution above.