Recopier et complete chaque egalite 5 sur 18 plus 5 sur ... egale 5 sur 6 7 sur 12 plus ... sur 3 egale 1 sur 4 ... sur ... plus 5 sur 36 egale 1 sur 9

5/18 + 5/9 = 5/6

==> Justification

5/6 - 5/18 = 5x3 / 6x3 - 5/18 = 15/18 - 5/18 = 10/18 = 5/9

7/12 + (-1)/3 = 1/4

==> Justification

1/4 - 7/12 = 1x3 / 4x3 - 7/12 = 3/12 - 7/12 = -4/12 = -1/3

-1/36 + 5/36 = 1/9

==> Justification

1/9 - 5/36 = 1x4 / 9x4 - 5/36 = 4/36 - 5/36 = -1/36