The ideal length of a particular metal rod is 30.5 cm. The measured length may vary from the ideal length by at most 0.015 cm. What is the range of acceptable lengths for the rod.

The range can be expressed as:

which agrees with answer D

Step-by-step explanation:

If the tolerance is 0.015 cm for the final rod, then the range of acceptable lengths for the rod is between 30.5 - 0.05 and 30.5 + 0.015 . That is between

30.485 cm and 30.515 cm

Which can be expressed as:  

x = 12

y = 1

for the points!