Can i have the 3 answers plz?

For the inequality |c| < |d| to be true, which of the following must be true?

Write an inequality for this description. - one fourth of the opposite of the difference of five and a number is less than twenty.

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.