Ajuda ai eu dou melhor resposta quem fizer gracinha ei denunci...

a) 28+[50-(24-2)-10]=

28+[50-22-10]=

28+[28-10]=

28+18=

46

b) 20+[13+(10-6)+4]=

20+[13+4+4]=

20+[17+4]=

20+21=

41

c) 52-{12+[15-(8-4)]}=

52-{12+[15-4]}=

52-{12+11}=

52-23=

29

d) 25+{12+[2-(8-6)+2]}=

25+{12+[2-2+2]}=

25+{12+[0+2]}=

25+{12+2}=

25+14=

39

e) {[(18-3)+(7+5)-2]+5}-12=

{[15+12-2]+5}-12=

{[27-2]+5}-12=

{25+5}-12=

30-12=

18