Which property can you use to show that 3x + (2x + 4) is equivalent to (3x + 2x) + 47

What is the sum of these mixed numbers 2 1/8 + 4 3/8

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.