Long piece is 81 inches
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Explanation:
x = length of short piece
3x = length of the longer piece (3 times longer)
x+3x = 4x = total length
total length = 108
So 4x = 108 is the equation which solves to x = 27 after dividing both sides by 4.
The short piece is x = 27 inches and the long piece is 3*x = 3*27 = 81 inches. Adding the two pieces gives 27+81 = 108 which helps confirm the answer.