2) Calcule: a) 9(10+2)= 9(2+5)-10(6-2)= c) 54:(9.3-3.3)+3.1= d) 6(42:7-4)-0:3= e) (4.8:2):8+2.5= 256:(32:2:2:2):4= g) [15+2(3+4)]= [45-(3.5-2)]:8= i) 6[(36:9-3)cdot (8:2)]:3= j) 6.8+[48:12-48:(4+12)]= 1) 48-2[125:5-(8-36:6)]:2=

Vamos calcular cada uma das expressões fornecidas:<br /><br />a) $9(10+2) = 9 \times 12 = 108$<br /><br />b) $9(2+5)-10(6-2) = 9 \times 7 - 10 \times 4 = 63 - 40 = 23$<br /><br />c) $54:(9.3-3.3)+3.1 = 54 \div (9.3 - 3.3) + 3.1 = 54 \div 6 + 3.1 = 9 + 3.1 = 12.1$<br /><br />d) $6(42:7-4)-0:3 = 6 \times (42 \div 7 - 4) - 0 \div 3 = 6 \times (6 - 4) - 0 = 6 \times 2 - 0 = 12 - 0 = 12$<br /><br />e) $(4.8:2):8+2.5 = (4.8 \div 2) \div 8 + 2.5 = 2.4 \div 8 + 2.5 = 0.3 + 2.5 = 2.8$<br /><br />f) $256:(32:2:2:2):4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4 = 256 \div (32 \div 2 \div 2 \div 2) \div 4