Answer:
Picture is blurr. kindly upload clear pic
Answer:
They want you to put it into an expression so that it could be expressed. So, 8 more than n would be 8+n.
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How to get answer by Mimiwhatsup (In Decimal Form):

Answer in Fraction Form: 
9.4 Ft for the first one
7.5 Ft for the second piece
12 Ft for the Third
he uses 5.2 Ft from the first piece of wood so 9.4 - 5.2= 4.6ft
he uses 6.1 ft from the second piece of wood , 7.5 - 6.1 = 1.4 ft
Nathan didnt use any of the 3rd piece of wood , so he still have 12 Feet of wood remaining so, 12+4.6+1.4 = 18 feet of wood left that he didnt use.