PLEASE HELP ME 6+__=8 and you will get brainliest :)

Triangle abc is reflected over the line y=x triangle abc has points (-6,-,-1) and (-5,-6) what is the c coordinate

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%

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?