PLEASE HELP ME, THIS IS FOR MY FINAL TEST

What is x and y (use substitution? ) 5x+3y=38 and y=3x+8?

Find the actual dimensions of the box. the side length are in meters and integers. the surface area of the box is 104 m2 and volume of the box is 60 m3.

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.