Salut,
Exercice 41:
A=2/3 x 4/5
=2x4/3x5
=8/15
Exercice 45:
a) -3/8 x 16/6
-3x16/8x6
-3x2x8/8x3x2
= -1
b)15/2x-12/-5
=15x12/2x5
=5x3x6x2/2x5
=18
c)-14/25 x 15/-7
=14 x 15 / 25 x 7
=7x2x3x5/5x5x7
=2 x 3 / 5 = 6/5
d)5/11 x 66/15
=5x66/11x15
=5x6x11/11x3x5
=6/3
=2
Et de rien