So first off, the answer to this is 24 now think of x as the real or original sum or amount, also y as the new sum or amount. y * 1.5 is x, and y+12 is x. Now flip that to figure out what is y, also which is what we need, and you have x/1.5 = y as well as x-12 = y. Use the equal values method and make an equation x/1.5=x-12. solve this equation to get x, which is 36. to figure out the new amount, y, you need to minus 12, which can help you get the answer which is 24.
D. None. Say the obtuse angle is 100 degrees. Since the sum of all angles in a triangle cannot be bigger than 180, it's not possible because 195 (100+95) is greater than 180 degrees.