a) (80 X 81):2 = 40 X 81
=3 240
b)100 : 2 = 50
2 X [50 X (50 : 2)+25]
2 X (50 X 25 +25)
2 X (1250 + 25)
2 X 1275
2550
c)99 -1 = 98
98 : 2 = 49
2 x [98 x (98 : 2) +49]
2 X (98 X 49 :2) +49
2 X (4802 :2) + 49
2 X 4851
9702
a) 3240, b)2550, c) 9702.
Sper ca te-am ajutat !!!
Coronita te rog!!!