Question

5. Elimine os parênteses e os colchetes e calcule o valor de: a) 35 + [–21 – (–12 + 15)] b) –20 – [21 + (–20 – 16) + 11] c) 20 – (16 + 17) – [15 – (18 – 23)] d) – (–30) – [37 + (35 – 31 – 34) – 36]

Answer 1

a) 35 + [–21 – (–12 + 15)]

35 + [-21 - (3)]

35 + (-24)

35 - 24

11

b) –20 – [21 + (–20 – 16) + 11]

-20 - [21 + (-36) + 11]

-20 - [21-36+11]

- 20 - (-4)

- 20 + 4

-16

c) 20 – (16 + 17) – [15 – (18 – 23)]

20 - 33 - [15 - (-5)]

-13 - 15 + 5

-28 + 5

-23

d) – (–30) – [37 + (35 – 31 – 34) – 36]

30 - [ 37 + (-30) - 36 ]

30 - 37 - 30 - 36

-133