a) 31x12x14=384x14=5376
211x12x3=2532x3=7596
(45+15)x105=60x105=6300
(30+20)x1=50x1=50
b) 525x(729-719)=525x10=5250
916x(23-21)=916x2=1832
405x(55-33)=405x22=8910
45x(25-25)=45x0=0
c) (41+39)x63=80x63=5040
(215+385)x7=600x7=4200
(17+32)x51=49x51=2499
18+12=30
CU PLACERE!