Where do the X go? (I'm going to give out a lot of points :D)

Part a : solve - vp + 40 < 65 for v . part b : solve 7w - 3r = 15 for r show your work!

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

If a suspect is in possession of 20 grams of cocaine how many ounces does he possess what will the charge be