Réponse:
•2
D=-13/6+5/7
=13×7/6×7+5/6/7×6
=91/42+30/42
= -62/42
E=5×3/8×3-13×4/6×4
=15/24 - 52/24
= -37/24
F=5/2 - 11/4
=5×2/2×2 - 11/4
=10/4 - 11/4
=-1/4
•3
a.greg aurait pu prendre 6 pour dénominateur commun.
b.G=5/3-7/6=5×6/3×6-7×3/6×3=30/18-21/18=9/18
G=5/3-7/6=5×2/3×2-7/6=10/6-7/6=3/6 9/18=9÷9/18÷9=1/2
