(6*6):4*8:((3-(9:9*1+9)*0)*3

(6 * 6) : 4 * 8 : ((3 - (9 : 9 * 1 + 9) * 0) * 3 = 72

1) 6 * 6 = 36
2) 9 : 9 = 1
3) 1 * 1 = 1
4) 1 + 9 = 10
5) 10 * 0 = 0
6) 3 - 0 = 3
7) 36 : 4 = 9
8) 9 * 8 = 72
9) 72 : 3 = 24
10) 24 * 3 = 72