2 c 5 ) 4 =- 12 July 8, 2019 16 32 64 128 2 c 5 )+ 4 =- 12 4 2 c )- 5 1 3 9 12c B 2 c 3 8bc 4 12c 5 2 5 c 2 c 4 5 d 20 2 5 - 4
