6a2b × (-3a3b8) = -18a5b9
0,2m3n9 × 2,5m4n = 0.5m7n10
0,75a9b3c2 × 11/3a4bc7 = 1a13b4c9
-14a7b3c11 × 23/7bc4 = -34a7b4c15