Réponse :
bonjour
Explications étape par étape :
1/4 / 4
=1/4 x 1/4
= 1/16
-6/-21 x -14/8
=6/21 x -7/4
= 3x2/3x7 / -7/2x2
=-1/2
2/3 - 5/2
=2x2/3x2 - 5x3/2x3
=4/6 - 15/6
=-11/6
2/3 / 3/2
=2/3 x 2/3
=4/9
3- 4/5
= 15/5 - 4/5
=11/5
-4 x 14.312 x (-0.25)
=-4 x 14.312 x -1/4
= 14.312
