Like and subscribe if you enjoyed this video! Trying to reach 1000 subscribers because of the new YouTube policy.
E=-25/2. See Pitch Perfect Cup Song played by a pencil:
E - 4E - 7 - 7E - 4 + 7E + E = 14
E - 4E - 7E + 7E + E = 14 + 7 + 4
-2E = 25
E = -25/2