1. 12*31-8 = 364
1) 12*31 = 372
2) 372-8 = 364
2. 42*72-9 = 3.015
1) 42*72 = 3.024
2) 3.024-9= 3.015
3. 34*53-13 = 1.789
1) 34*53= 1.802
2) 1.802-13=1.789
4. 22*16 = 352
