7v=4v-32 how do i solve this

What is the average rate of change for this function for the interval from x=2 to x=4 ?

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?

If the segment op is dilated by a scale factor r=2, what is the length of segment op? a)10cm b)16cm c)6cm d)4cm