6. Calculează:
a) 9 x 9 +9:9 + 9 =
45: 9 + 5 x 5 + 45 =
63:7 +5x7 + 23 =
36:4:3+4x4:4+30:5x7=
b) (45 : 5 + 36 : 6 + 10): 5+3 x 8:6 =
9 x (3 + 4) + 80: (2 + 6) + 8 =
5x (6 + 2) + 36 : (2 + 4) + 4=
(63: 7 + 48: 6 + 13): 6 + 8x7:8 =
c) (56: 7 + 36:6 +26): (8 x 5: 4 + 42: 6 - 13) =
(35:5 +48 : 6 + 20): (15:3+ 3 x 8:4 - 4) =
(72:8 + 24 : 4 + 25): 8 + (6 x 7): 6 =​