A) 4 1/12 - 1 5/6X = 2 17/24
4 1/12 - 2 17/24 = 1 5/6X
4 2/24 - 2 17/24 = 3 26/24 - 2 17/24 = 1 9/24 = 1 3/8
б) 3 1/3:(3/7X - 13/15) = 1 9/16
3/7X - 13/15 = 3 1/3 :1 9/16
3 1/3 :1 9/16 = 10/3:25/16 = 10/3*16/25= 32/15 = 2 2/15
3/7X = 2 2/15 + 13/15
3/7X = 2 15/15 = 3
X = 3:3/7 = 3*7/3 = 7