Which expression is equivalent to (5-2i)^2-i^3 where i^2=-1?

2x - 20 = 32 20 - 3x = 8 6x - 8 = 16 -13 - 3x = -10

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

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%