Помогите, 5/6+5/18-(3целых7/9-2целых13/15)=?

5/6 + 5/18 - (3 7/9 - 2 13/15) = 1/5  1) 3 7/9 - 2 13/15 = 3 35/45 - 2 39/45 = 2 80/45 - 2 39/45 = 41/45 2) 5/6 + 5/18 = 15/18 + 5/18 = 20/18 = 1 2/18 = 1 1/9 3) 1 1/9 - 41/45 = 1 5/45 - 41/45 = 50/45 - 41/45 = 9/45 = 1/5 Пояснения: 7/9 = (7*5)/(9*5) = 35/45 - доп.множ. 5 13/15 = (13*3)/(15*3) = 39/45 - доп.множ. 3 3 35/45 = 2 45/45 + 35/45 = 2 80/45 5/6 = (5*3)/(6*3) = 15/18 - доп.множ. 3 2/18 = (2:2)/(18:2) = 1/9 - сократили на 2 1/9 = (1*5)/(9*5) = 5/45 - доп.множ. 5 1 5/45 = 45/45 + 5/45 = 50/45 9/45 = (9:9)/(45:9) = 1/5 - сократили на 5