Why is it important for scientists to develop definitions for standard measurements that don’t rely on a physical object

What is the most accurate measurement of 1 pound

What is the length of the segment joining the points at (4,5) and (6,-2) round to the nearest tenth if necessary

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.