А) 3 1/2+1/2: б) 3 1/2+7: в) 2 3/8+3 5/8: г) 3 2/3+1 2/3: д) 5/7+5 4/7: е) 5 2/9+2 1/9

А) 3 1/2 + 1/2 = (3 * 2 + 1)/2 + 1/2 = 7/2 + 1/2 = (7 + 1)/2 = 8/2 = 4;

б) 3 1/2 + 7 = (3 * 2 + 1)/2 + 7 = 7/2 + 14/2 = (7 + 14)/2 = 21/2;

в) 2 3/8 + 3 5/8 = (2 * 8 + 3)/8 + (3 * 8 + 5)/8 = (16 + 3)/8 + (24 + 5)/8 = 19/8 + 29/8 = (19 + 29)/8 = 38/8 = 19/4;

г) 3 2/3 + 1 2/3 = (3 * 3 + 2)/3 + (1 * 3 + 2)/3 = 11/3 + 5/3 = 16/3;

д) 5/7 + 5 4/7 = 5/7 + (5 * 7 + 4)/7 = 5/7 + 39/7 = 44/7;

е) 5 2/9 + 2 1/9 = (5 * 9 + 2)/9 + (2 * 9 + 1)/9 = 47/9 + 19/9 = 66/9 = 22/3.