Root 225 rational or irrational? plzz help urgent.

Figure lmno is located at l (1, 1), m (4, 4), n (7, 1), and o (4, −2). use coordinate geometry to best classify quadrilateral lmno.

You are on a cycling trip around europe with friends. you check the weather forecast for the first week. these are the temperatures for the week. sun mon tues wed thurs fri sat 16°c 20°c 24°c 28°c 28°c 23°c 15°c what is the mean temperature forecast for the week?

How do you use the elimination method for this question? explain, because i really want to understand!