Réponse:
A=-4+7-(-2)-3
=-4+7+2-3
=7+2-4-3
=9-7
A=2
c=(1-4/5):(-2/5)
=5-4/5:-2/5
=1/5:-2/5
=1/5/grande barre-2/5
=1/5×-5/2
=on simplifie les 5 il reste donc
=1/2
c=1/2
