Select all equations that are true. A. 3 4 − 1 2 = 1 4 B. 9 16 − 4 8 = 5 8 C. 7 8 − 3 4 = 1 8 D. 7 15 − 1 3 = 6 15 E. 1 2 − 1 20 = 10 20