Question

40-{15+[8+(2-7-8)-20]+1}-20=

Answer 1

OK, boa noite.

40-{15+[8+(2-7-8)-20]+1}-20

40 -{ 15+ [8-13-20]+1}-20

40-{15 -25 +1}-20

40 - { -9} -20

40 + 9 - 20

49 - 20

29 → Resultado.