Réponse:
exo 1:
A= 20+(-3)+(-20)×(-3)
= 20+(-3)+60
=20-30+60
A = 50
B= (-36)-(-48,3)+(+21,4)-(+18)+10,3
= -36+48,3+21,4-18+10,3
B = 26
C= (3⁴-3,21×100)+2³
=( 81-3,21×100) + 8
= (81-321)+18
= -240 +18
C = -222