X^2+4x=13 solve by equations by completing the square. show all work

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 area of the original rectangle? 8 cm² 20 cm² 25 cm² 40 cm²

Why is x= 4 a solution to the proportion 14/x 56/1 6