SOLUCIÓN DE EJERCICIOS

Ejercicio 1
[(5-8)+3]-[4+(8-15)] = (-3+3)-(4-7)
                                  = 0-(-3)
                                  = 3

Ejercicio 2
[(-2)+(-4+5)]+[(5+4)-(-2+8)] = (-2+1)+(9-6)
                                               = -1+3
                                               = 2

Ejercicio 3
[3+4-(-7)]-[(5+4)-(-5)] = (7+7)-(9+5)
                                     = 14-14
                                     = 0

Ejercicio 4
[(7+8-4)+(-13)]+[(9-4)-(6+5)] = (11-13)+(5-11)
                                                 = -2-6
                                                 = -8