Вычислите 1)1/7+1/5+1/3 2)7/10+2/15+11/30 3) ( 2/3+9/11)×22 4) 3/5: (9/10-3/5×8/9 заранее

1) 1/7+1/5+1/3 = 15/105 + 21/105 + 35/105 = 71/105

2) 7/10+2/15+11/30 = 21/30 + 4/30 + 11/30 = 36/30 = 1 6/30 = 1 1/5 или 1,2

3) (2/3+9/11)*22 = 2/3*22 + 9/11*22 = 44/3 + 18 = 44/3 + 54/3 = 98/3 = 32 2/3

4) 3/5:(9/10-3/5*8/9) = 1 7/11
1. 3/5*8/9 = 8/15
2. 9/10-8/15 = 54/60 - 32/60 = 22/60 = 11/30
3. 3/5:11/30 = 3/5*30/11 = 18/11 = 1 7/11