Which of the following identifies all of the integer solutions of the equation |x| = 21? 0 and 21 -21 only 21 only 21 and -21

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

You are at a restaurant and owe $56.20 for your meal. you want to leave an 18% tip. approximately how much is your tip?

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?