Panther90 if u r still out there it is potterhead42

If a and −a are numbers on the number line, which expression must give the distance between them? a) 0 b) a c) |2a| d) |a|

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.

The distance between two points is 6.5cm and scale of map is 1: 1000 what's the distance between the two points