Verified answer

а) 7/12y = 1 1/4

y = 1 1/4 : 7/12 = 5/4 : 7/12 = 5/4 * 12/7 = 15/7 = 2 1/7

y = 2 1/7

б) a - 13/18a = 1/3

5/18a = 1/3

a = 1/3 : 5/18 = 1/3 : 18/5 = 6/5 = 1 1/5

a = 1 1/5

в) 2 2/3 : x = 1 1/9

x = 2 2/3 : 1 1/9 = 8/3 : 10/9 = 8/3 * 9/10 = 12/5 = 2 2/5

x = 2 2/5