1)

2) 1 + (4.24 +(-1.2) : (-0.6) : (-0.1))

1 + (4.24 - 1.2 : (-0.6) : (-0.1))

1 + (4.24 + 2 : (-0.1))

1 + (4.24 - 20)

1 - 15.76 = - 14.76

3) | х + 2.51 | = 8

| х | = 8 - 2.51

| х | = 5.49

х = 5.49