1) ( + 3) – ( - 7) + ( - 4) – ( + 5) =2) ( - 4) – ( - 4) – ( + 2) + ( - 3) =3) ( - 8) – ( - 9) + ( + 5) – ( + 2) =4) 15 - (17 + 2) =5) 12 - ( - 2 - 14) =6) - 15 + (3 - 13) =7) 7 + (2 – 3) – (1 – 4) =8?

1) ( + 3) – ( - 7) + ( - 4) – ( + 5) = 3 + 7 - 4 - 5 = 10 - 9 = 1

2) ( - 4) – ( - 4) – ( + 2) + ( - 3) = - 4 + 4 - 2 - 3 = 0 - 5 = - 5

3) ( - 8) – ( - 9) + ( + 5) – ( + 2) = - 8 + 9 + 5 - 2 = - 10 + 14 = 4

4) 15 - (17 + 2) = 15 - 17 - 2 = 15 - 19 = - 4

5) 12 - ( - 2 - 14) = 12 + 4 + 14 = 30

6) - 15 + (3 - 13) = - 15 + 3 - 13 = - 28 + 3 = - 257) 7 + (2 – 3) – (1 – 4) = 7 + 2 - 3 - 1 + 4 = 13 - 4 = 9

8) - 1 – (2 – 4) + (2 – 4) = - 1 - 2 + 4 + 2 - 4 = elimino n° que son iguales con signo distinto - 1 = - 1 9) 6 .

( - 3) + 5.

( - 2) + ( - 4) .

( - 5) = - 18 + ( - 10) + 20 - 18 - 10 + 20 = - 28 + 20 = - 8

10) - 2 .

[ - 3 + 4 .

( - 5 - 2)] = - 2 .

[ - 3 + 4 .

( - 7)] = - 2 .

[ - 3 + ( - 28)] = - 2 .

[ - 31] = + 62

11) 2 – 3 .

[(5 – 2) .

(3 – 6) + 8] = 2 – 3 .

[(3) .

( - 3) + 8] = 2 – 3 .

[( ( - 9) + 8] = 2 – 3 .

[ - 1] = 2 – [ - 3] = 2 + 3 = 12) 20 – 9 .

2 – ( - 5) .

( - 2) =

13) 2 .

(3 + 5) – (8 – 1) + ( - 1) .

(3 + 1) – 8 =.