T^2-15t+56
factor each polynomial

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

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%

Biggest exam of the which of the following are polynomial functions?