Which expression is equivalent to (3k-2i)squared, where i is the imaginary unit?

Which best explains why this triangle is or is not a right triangle?

True or false look at the picture pls : /

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?