Вычислите: 1) 5/11+3/11; 3) 6+5/13; 5) 4 11/18 - 1 5/18; 2) 7/15 - 4/15; 4) 2 4/13 + 5 2/13; 6) 7 2/9 - 2 5/9.

1) 8/11; 2) 3/15=1/5; 3) 6 5/13; 4) 7 6/13; 5) 3 6/18=3 1/3; 6) 5 2/9 - 5/9 = 4 11/9 - 5/9 = 4 6/9 = 4 2/3.