помогите -2целых1/6+(-0,9)+3целых1/15 пж дам 60 баллов

-2 1/6 + (-0,9) + 3 1/15 = 1/2
1) -2 1/6 + (-0,9) = -13/6 + (-9/10) = -80/30 + (-27/30) = -80/30 - 27/30 = -107/30 = -3 17/30
2) -3 17/30 + 3 1/15 = -3 17/30 + 3 2/30 = -15/30 = 1/2