Verified answer

1)  67/90 - 50/90 + 2/90 = 17/90 + 2/90 = 19/90.

2)  23/30 + 5/30 - 19/30 = 28/30 - 19/30 = 9/30 = 3/10 = 0,3.

Ответы: 19/90; 0,3.