I need assistance can I get help

Which of the following is a function? a.) {(-2, -4/5), (-1,-,,-1)} b.) {(-2,,1/,3/,1)} c.) {(-22)} d.) {(-21)}

Which number line represents the solution set for the inequality - x 24?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.