Математика, сделайте с решением​

1) 3/11 + 5/22 = 6/22 + 5/22 = 11/22 = 1/2

2) 11/12 - 7/15 = 55/60 - 28/60 = 27/60 = 9/20

3) 11/15 - 3/20 + 1/30 = 44/60 - 9/60 + 2/60 = 37/60

а)3/11 + 5/22 = 6/22 + 5/22 = 11/22 = 1/2

б)11/12 - 7/15 = 55/60 - 28/60 =27/60=9/20

в) 11/15 - 3/20 + 1/30 = 44/60 - 9/60 + 2/60 = 37/60