vă rog urgent c,d,e,f! Dau coroana!

Explicație pas cu pas:
c)3²×8:12×13:39
9×8:12×13:39
72:12×13:39
6×13:39
78:39
=2
d)5×12×17:255
60×17:255
1020:255
=4
e)12×11:44×16:24
132:44×16:24
3×16:24
48:24
=2
f)456:24×5²:19×20
456:24×25:19×20
19×25:19×20
475:19×20
25×20
=500