Simplifie le plus possible

Bonjour,

A = 2/5 - 7/9 + 2/15
A = 2 x 9 / 5 x 9 - 7 x 5 / 9 x 5 + 2 x 3 / 15 x 3
A = 18/45 - 35/45 + 6/45
A = 24/45 - 35/45
A = - 11/45

B = 1/8 + 5/2 x 1/3
             2/7
B = 1/8 + 5/6
          2/7
B = 1 x 6 / 8 x 6 + 5 x 8 / 6 x 8
                   2/7
B = 6/48 + 40/48
            2/7
B = 46/48 : 2/7
B = 46/48 x 7/2
B = 322/96
B = 2 x 161 / 2 x 48
B = 161/48