Someone please help me

What expression is equivalent to 42x-56y

The los angels ram scored 26, 30, 48, and 31 pts in their last four games. how many pts do they need to score in super bowl liii in order to have an exact mean average of 35 pts over five games. write and solve and equation. use x to represent the 5th game.

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%