A carpenter is cutting a 2 by 4 for the framing of a roof. The length needs to be 5 feet. He allows 0.1-foot possible variation for the length of the cut. What values of l represent the acceptable lengths for the board, in feet?

5-0.1 <= length <= 5+0.1

To find the acceptable lengths for the board, we need to consider the given length needed (5 feet) and the possible variation (+/- 0.1 feet).

To determine the acceptable lengths, we subtract and add the possible variation from the needed length:

Acceptable Length = (Needed Length) - (Possible Variation)

Acceptable Length = 5 feet - 0.1 feet

Acceptable Length = 4.9 feet

Therefore, the acceptable length for the board is 4.9 feet.