Répondre :
5b+7=12
5b= 5
b= 5/5 = 1
8+4b=20
4b=12
b=12/4 =3
31=3+7b
28=7b
28/7 = b
b=4
2b+11=11
2b=0
b=0
d c d c t b : 5b +7=12 8+4b=20 31=3+7b et 2b+11=11
5b+7=12
5b= 5
b= 5/5 = 1
8+4b=20
4b=12
b=12/4 =3
31=3+7b
28=7b
28/7 = b
b=4
2b+11=11
2b=0
b=0