2 10/13-4/9*2 10/13+1/6*2 10/13=36/13-4/9*36/13+1/6*36/13=36/13-16/13+6/13=26/13=2 ответ:2
ответ 2 =18/18к-8/18к+3/18к=13/18к подставим к =13/18 * 36/13 = 2