Bonjour
a. 2-1/3+1/6-1/9
= (2 x 18) / (1 x 18) - (1 x 6) / (3 x 6) + (1 x 3) / (6 x 3) - (1 x 2) / (9 x 2)
= 36/18 - 6/18 + 3/18 - 2/18
= 39/18 - 8/18
= 31/18
b.1+1/2+3/4+5/6
= (1 x 12) / (1 x 12) + (1 x 6) / (2 x 6) + (3 x 3) / (4 x 3) + (5 x 2) / (6 x 2)
= 12/12 + 6/12 + 9/12 + 10/12
= 37/12.
