Determine whether the study depicts an observational study or an experiment. thirty university students are divided into two groups. one group receives free tutoring in mathematics, the other doesn't. after one semester, scores on final mathematical examinations are compared. does the description correspond to an observational study or an experiment?

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

Can you simplify 4/7? 24 points will be awarded!

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.