I need some help please I’d really appreciate it this is due in 25 mins.

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

What is the anwers for 9+2x=5x-3-x

What are linear equations? could'ya explain too me, ? ! and how do you see what graph is a proportional relationship?