Peter is five times as old as kristin. in two year's time, peter will be three times as old as kristin. how old are they now? (how do you get the answer? )

Me write an equation for the interior angles of this triangle that uses the triangle sum theorem

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%

These tables represent a quadratic function with a vertex at (0, -1). what is the average rate of change for the interval from x = 9 to x = 10?