Someone help please

What will the graph look like for a system of equations that has no solution? a. the lines will be perpendicular. b. the lines will cross at one point. c. both equations will form the same line. d. the lines will be parallel.

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.

What is 6/10 rounded to the nearest half