What is the slope and y intercept of 15x+6y=-36

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

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%

Which statement is true about the local minimum of the graphed function? over the interval[-4,-2], the local minimum is 0. over the interval [-2,-1] , the local minimum is 25. over the interval [-1,4], the local minimum is 0. over the interval [4,7], the local minimum is -7