What are the three longest wavelengths for standing waves on a 220-cm-long string that is fixed at both ends?

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

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?

Factor and solve to find roots x squared -x - 90 =0