I’m reviewing for a test but i can’t remember how to do this

The track team ran a mile and a quarter during their practice how many kilometers did her team runs?

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.

Use the distance formula to find the distance between (-3,5) and (3,1)