## Algebra 1: Common Core (15th Edition)

The ideal length of a certain nail is 20 mm: $|x-20|$ The actual length can vary from the ideal length by at most 0.4 mm. Thus: $|x-20| \leq 0.4$ $-0.4 \leq x -20 \leq 0.4$ $19.6 \leq x \leq 20.4$ The range of acceptable lengths of the nail is between 19.6mm and 20.4mm.