(х-3 9/13)+5 10/13=12 4/13
(х-3 9/13)+5 10/13=12 4/13 х=12 4/13-5 10/13+3 9/13 х=10 3/13 (10 3/13-3 9/13)+5 10/13=6 7/13 +5 10/13= =11 17/13=12 4/13 12 4/13=12 4/13