What is the missing value in the proportion 4/5 = x/30

Choose the point slope form of the equation below that represents the like that passes through the points (-6,4) and (2, 0)

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.