Répondre :
prenons SF, BD, MD, QF.
SF= x
BD= 100+x
x=QF+20 = QF = x-20
x+(100+x)+(3x+20)+x-20=2500
x+x+3x+x=2500+20-(100+20)
4x=2400
x=2400/4
x=600
Subway France = 600
quick france=580
Brioche dorée= 700
McDonald's=1820
enfin je crois ^__^
SF= x
BD= 100+x
x=QF+20 = QF = x-20
x+(100+x)+(3x+20)+x-20=2500
x+x+3x+x=2500+20-(100+20)
4x=2400
x=2400/4
x=600
Subway France = 600
quick france=580
Brioche dorée= 700
McDonald's=1820
enfin je crois ^__^